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Your decisions.
Our calculators.

Mortgage Calculator

Calculate monthly payments, total interest, and view amortization schedules.

Home Affordability

Find out how much house you can afford based on your income and debts.

Rent vs Buy

Compare the true cost of renting versus buying a home over time.

Refinance Calculator

See if refinancing saves you money. Find your break-even point.

Mortgage Payoff

Calculate how extra payments reduce your payoff time and total interest.

FHA Loan Calculator

Estimate FHA loan payments including MIP and down payment requirements.

VA Mortgage Calculator

Calculate VA loan payments with no down payment and no PMI.

Home Equity Loan

See how much you can borrow against your home equity.

HELOC Calculator

Estimate payments on a Home Equity Line of Credit.

Down Payment Calculator

Calculate how much you need for a down payment and how long to save.

Closing Cost Calculator

Estimate closing costs when buying or refinancing a home.

Rent Calculator

Determine how much rent you can afford based on your income.

Amortization Calculator

View a detailed amortization schedule for any loan.

PMI Calculator

Estimate monthly PMI, loan-to-value ratio, and when mortgage insurance drops off.

Property Tax Calculator

Estimate annual and monthly property tax from home value and tax rate.

Mortgage Points Calculator

See if buying discount points is worth it and find your break-even point.

Biweekly Mortgage

See how biweekly payments shorten your loan and cut total interest.

ARM Calculator

Model an adjustable-rate mortgage: fixed period, rate caps, and worst-case payment.

Income Tax Calculator

Estimate your federal and state income tax liability.

Salary Calculator

Convert between annual, monthly, bi-weekly, weekly, and hourly pay.

Paycheck Calculator

Calculate your net paycheck after all withholdings and deductions.

Sales Tax Calculator

Calculate sales tax amounts by state and locality.

Self-Employment Tax

Estimate SE tax for freelancers, contractors, and business owners.

Capital Gains Tax

Calculate taxes on investment profits, short-term and long-term.

Estate Tax Calculator

Estimate federal estate tax on inherited wealth.

Marriage Tax Calculator

See how marriage affects your combined tax liability.

Hourly to Salary

Convert hourly wages to annual salary and vice versa.

Bonus Tax Calculator

Calculate how much of your bonus goes to taxes.

VAT Calculator

Calculate VAT-inclusive and VAT-exclusive prices for any tax rate.

Tax Bracket Calculator

Find your federal tax bracket, marginal rate, and effective rate.

Auto Loan Calculator

Calculate monthly car payments, total interest, and payoff schedule.

Credit Card Payoff

See how long to pay off your balance and how much interest you'll pay.

Debt Payoff Calculator

Create a debt payoff plan. Compare avalanche vs snowball methods.

Personal Loan

Calculate monthly payments and total cost of personal loans.

Student Loan Calculator

Estimate student loan payments and explore repayment plans.

Loan Calculator

General-purpose calculator for any type of fixed-rate loan.

Business Loan

Calculate business loan payments and compare financing options.

Debt Consolidation

See if consolidating your debts into one loan saves money.

Debt-to-Income Ratio

Calculate your DTI ratio and see how lenders evaluate your debt load.

Auto Lease Calculator

Compare leasing vs buying and estimate monthly lease payments.

Payment Calculator

Calculate the monthly payment on any loan amount.

Interest Calculator

Calculate simple or compound interest on any amount.

APR Calculator

Calculate the true Annual Percentage Rate including fees.

Boat Loan Calculator

Calculate monthly boat loan payments, total interest, and payoff schedule.

Lease Calculator

Calculate monthly lease payments based on price, residual value, and rate.

Repayment Calculator

Calculate loan repayment schedule with monthly payments and total interest.

Credit Card Calculator

Calculate how long to pay off credit card debt and total interest paid.

Cash Back vs Low Interest

Compare cash back rewards vs low interest rate financing.

Interest Rate Calculator

Calculate the interest rate on a loan from payment and term.

Retirement Calculator

Project your retirement savings and see if you're on track.

401(k) Calculator

Estimate your 401(k) balance with employer match and contributions.

Investment Calculator

Project growth of investments with compound interest over time.

Compound Interest

See the power of compound interest with regular contributions.

Roth IRA Calculator

Project tax-free growth in your Roth IRA account.

IRA Calculator

Compare Traditional and Roth IRA growth and tax benefits.

Social Security

Estimate your Social Security benefits at different retirement ages.

Pension Calculator

Estimate your pension payout based on years of service and salary.

Annuity Calculator

Calculate the future value of annuity payments.

RMD Calculator

Calculate Required Minimum Distributions from retirement accounts.

ROI Calculator

Calculate Return on Investment for any project or purchase.

Mutual Fund Calculator

Project mutual fund growth with fees and dividends.

Bond Calculator

Calculate bond yields, prices, and maturity values.

CD Calculator

Calculate Certificate of Deposit earnings at maturity.

Annuity Payout

Calculate monthly income from a lump sum annuity investment.

Average Return

Calculate compound annual growth rate (CAGR) of investments.

Finance Calculator

Solve for any variable in time value of money equations.

FIRE Calculator

Calculate your Financial Independence number and years to retire early.

Stock Profit Calculator

Calculate stock trading profit, loss, and return on investment.

Dividend Calculator

Calculate dividend yield, annual income, and projected growth.

CAGR Calculator

Calculate the compound annual growth rate of any investment.

Dollar-Cost Averaging

Project the future value of regular fixed investments over time.

Savings Calculator

Calculate how your savings grow over time with compound interest.

Cost of Living

Compare costs between cities and find equivalent salaries.

Budget Calculator

Create a monthly budget and track income vs expenses.

Inflation Calculator

See how inflation erodes purchasing power over time.

Emergency Fund

Calculate how much you need in an emergency savings fund.

Net Worth Calculator

Calculate your total net worth, assets minus liabilities.

Simple Interest

Calculate simple interest on savings or loans.

College Cost Calculator

Estimate the total cost of college and how much to save.

Tip Calculator

Calculate tips and split bills among groups.

Discount Calculator

Calculate savings from percentage or dollar discounts.

Currency Converter

Convert between currencies using live exchange rates.

Percent Off

Calculate the sale price and savings from a percentage discount.

Savings Goal

Find how long it takes to reach a savings goal, or the monthly amount needed.

50/30/20 Budget

Split your take-home pay into needs, wants, and savings.

Subscription Cost

Add up your monthly subscriptions and see the yearly total.

Sinking Fund

Save a set amount each month to reach a planned expense on time.

Rental Property

Analyze rental property returns, cash flow, cap rate, and ROI.

Real Estate Calculator

Comprehensive real estate investment analysis tool.

Commission Calculator

Calculate sales commissions with tiered rate structures.

Profit Margin Calculator

Calculate gross, operating, and net profit margins.

Depreciation Calculator

Calculate asset depreciation using multiple methods.

IRR Calculator

Calculate Internal Rate of Return on investments.

Present Value

Calculate the present value of future cash flows.

Future Value

Calculate the future value of investments or savings.

Break-Even Calculator

Find how many units or dollars you need to break even.

Payback Period

Calculate how long it takes to recoup an investment.

Markup Calculator

Turn cost and markup into selling price, profit, and margin.

Gross Rent Multiplier

Screen rental deals fast with the GRM ratio.

Cash-on-Cash Return

Measure annual cash flow against the cash you invested.

EBITDA Calculator

Calculate EBITDA and margin from your income statement.

BMI Calculator

Calculate your Body Mass Index to see if your weight is in a healthy range.

Body Fat Calculator

Estimate body fat percentage using the U.S. Navy method.

Lean Body Mass

Calculate lean mass and fat mass from weight and body fat percentage.

One Rep Max

Estimate your 1RM using Brzycki, Epley, and Lander formulas.

Target Heart Rate

Calculate heart rate zones for optimal training.

Body Type

Determine your body type, ectomorph, mesomorph, or endomorph.

Body Surface Area

Calculate BSA using Du Bois and Mosteller formulas.

BAC Calculator

Estimate blood alcohol content based on drinks, weight, and time.

Pace Calculator

Calculate running or walking pace per mile and per kilometer.

Army Body Fat

Estimate body fat using the DoD tape test method.

Overweight Calculator

Find out how many pounds above or below a healthy weight.

FFMI Calculator

Fat-Free Mass Index, better than BMI for athletes and lifters.

Max Heart Rate

Estimate your maximum heart rate and personalized training zones.

Waist-to-Height Ratio

Calculate WHtR, a simple predictor of central-fat health risk.

Calorie Deficit

Find the daily calorie target and deficit to reach your weight goal.

Calorie Calculator

Estimate daily calorie needs based on age, sex, height, weight, and activity.

BMR Calculator

Calculate your Basal Metabolic Rate using Mifflin-St Jeor formula.

Macro Calculator

Calculate optimal daily protein, carbs, and fat intake.

Ideal Weight

Find your ideal weight using Devine, Robinson, Miller, and Hamwi formulas.

TDEE Calculator

Calculate Total Daily Energy Expenditure for accurate calorie tracking.

Protein Calculator

Determine optimal daily protein intake based on weight and goals.

Fat Intake

Calculate recommended daily fat intake from calorie target.

Carbohydrate Calculator

Calculate remaining carb intake after protein and fat targets.

Healthy Weight

Find your healthy weight range based on height and BMI guidelines.

Calories Burned

Estimate calories burned during various physical activities.

Water Intake

Calculate recommended daily water intake based on weight and activity.

VO2 Max Calculator

Estimate cardiovascular fitness with Cooper or Rockport tests.

Pregnancy Calculator

Calculate due date, current week, and trimester from last period.

Ovulation Calculator

Calculate ovulation date and fertile window from cycle data.

Pregnancy Weight Gain

Calculate recommended weight gain during pregnancy by BMI.

GFR Calculator

Estimate glomerular filtration rate to assess kidney function.

Due Date Calculator

Calculate your estimated due date and current week of pregnancy.

Conception Calculator

Estimate conception date and window from due date or birth date.

Period Calculator

Predict next period dates, fertile windows, and ovulation.

Waist-to-Hip Ratio

Calculate WHR and assess health risk from fat distribution.

Pregnancy Weeks

Track pregnancy week by week with milestones and baby size.

Percentage Calculator

Find X% of a value, what percentage one number is of another, and more.

Percent Error

Calculate percent error between experimental and actual values.

Ratio Calculator

Simplify ratios and solve proportions.

Half-Life Calculator

Calculate remaining amount after exponential decay.

Exponent Calculator

Calculate the result of raising a base to any power.

Log Calculator

Calculate logarithms with any base, natural, common, binary.

Root Calculator

Calculate square root, cube root, or any nth root.

Scientific Notation

Convert numbers to and from scientific notation.

Quadratic Formula

Solve ax² + bx + c = 0 using the quadratic formula.

Slope Calculator

Calculate slope, y-intercept, and line equation from two points.

Fraction Calculator

Add, subtract, multiply, or divide fractions.

LCM Calculator

Find the Least Common Multiple of two or three numbers.

GCF Calculator

Find the Greatest Common Factor of two or three numbers.

Factor Calculator

Find all factors and prime factorization of a number.

Prime Factorization

Find the prime factorization of any number.

Rounding Calculator

Round numbers to any decimal place.

Long Division

Perform long division with step-by-step work shown.

Random Number Generator

Generate random numbers within a specified range.

Binary Calculator

Perform arithmetic on binary numbers with base conversions.

Hex Calculator

Arithmetic with decimal, hex, binary, and octal conversions.

Matrix Calculator

Calculate determinant, inverse, transpose, and eigenvalues.

Significant Figures

Count sig figs and round to specified precision.

Area Calculator

Calculate area of rectangles, circles, triangles, and more.

Volume Calculator

Calculate volume of cubes, spheres, cylinders, and cones.

Surface Area

Calculate surface area of 3D shapes.

Circle Calculator

Calculate diameter, circumference, and area from radius.

Triangle Calculator

Calculate triangle area, perimeter, and angles.

Right Triangle

Calculate hypotenuse, area, and angles of right triangles.

Pythagorean Theorem

Apply a² + b² = c² to find missing sides.

Distance Calculator

Calculate distance and midpoint between two points.

Rectangle Calculator

Calculate area, perimeter, and diagonal of a rectangle.

Cylinder Calculator

Calculate the volume and surface area of a cylinder.

Cone Calculator

Calculate cone volume, slant height, and surface area.

Sphere Calculator

Calculate the volume, surface area, and circumference of a sphere.

Standard Deviation

Calculate standard deviation, variance, and mean for a dataset.

Average Calculator

Calculate mean, sum, count, minimum, and maximum.

Mean Median Mode Range

Find mean, median, mode, and range of a dataset.

Z-Score Calculator

Calculate z-score and probability within a normal distribution.

Confidence Interval

Calculate confidence interval for a population mean.

Sample Size

Determine required sample size for surveys and studies.

P-value Calculator

Calculate p-value from z-scores and t-scores.

Probability Calculator

Calculate probability, odds, and complementary probability.

Statistics Calculator

Get complete descriptive statistics for a dataset.

Permutation & Combination

Calculate permutations (nPr) and combinations (nCr).

Number Sequence

Generate arithmetic or geometric sequences.

Midpoint Calculator

Find the midpoint, distance, and slope between two points.

Modulo Calculator

Calculate the remainder and quotient of a division.

Perimeter Calculator

Calculate the perimeter of common shapes.

Age Calculator

Calculate your exact age in years, months, and days. Find out how many days you have lived and when your next birthday falls.

Date Calculator

Add or subtract days, months, and years from any date to find the resulting date quickly and accurately.

Time Calculator

Add or subtract two time values to get a combined result in hours, minutes, and seconds.

Hours Calculator

Calculate the number of hours and minutes worked between a start time and end time, minus any break time.

Time Duration Calculator

Find the exact duration between two dates in years, months, days, weeks, hours, and minutes.

Day Counter

Count the total number of days, weeks, weekdays, and weekend days between two dates.

Day of the Week Calculator

Find out what day of the week any date falls on, plus the day number and week number of the year.

Time Zone Calculator

Convert time between different time zones worldwide. Supports all major time zones including EST, PST, GMT, CET, IST, and JST.

Sleep Calculator

Calculate your total sleep duration, number of sleep cycles, and get a sleep quality assessment based on your bedtime and wake time.

Time Card Calculator

Calculate your weekly hours, regular and overtime pay from daily work hours and your hourly rate. Track time cards and paychecks easily.

GPA Calculator

Calculate your Grade Point Average on the 4.0 scale by entering your course grades and credit hours.

Grade Calculator

Calculate your weighted average grade and letter grade based on assignment scores and their weights.

Final Grade Calculator

Calculate the score you need on your final exam to achieve a target overall grade.

Weighted GPA Calculator

Calculate a weighted high school GPA that accounts for the difficulty boost from Honors and AP/IB courses.

Cumulative GPA Calculator

Combine your prior cumulative GPA with a new semester GPA to get your updated cumulative GPA.

Test Score Calculator

Convert raw correct/total scores into a percentage and the corresponding US letter grade.

Reading Time Calculator

Estimate how long it takes to read a given word count at your preferred reading speed.

Study Time Calculator

Free study time calculator. Enter your credit hours to see weekly study hours, total hours until the exam, and a daily schedule using the 2 to 3 hours per credit rule.

Attendance Percentage Calculator

Work out your current attendance percentage and plan ahead: see how many remaining classes you must attend and how many you can safely skip.

SAT Score Calculator

Add your EBRW and Math section scores into an SAT total out of 1600, see an estimated percentile, superscore across two attempts, and a readiness note.

Password Generator

Generate strong, random passwords with customizable length and character types. Includes password strength rating.

Bandwidth Calculator

Calculate how long it takes to download a file based on file size and internet connection speed.

Shoe Size Conversion

Convert shoe sizes between US, EU, UK, and centimeter measurements for both men and women.

Conversion Calculator

Convert between common units of length, weight, temperature, and volume quickly and accurately.

Roman Numeral Converter

Convert any number to Roman numerals. Supports numbers from 1 to 3,999.

Dice Roller

Roll virtual dice with customizable number of dice and sides. Shows individual rolls, sum, average, and statistics.

IP Subnet Calculator

Calculate subnet mask, network address, broadcast address, and usable host range from any IP address and CIDR prefix.

Color Converter

Convert colors between RGB, Hex, HSL, HSV, and CMYK formats instantly. Enter any RGB value and see all conversions.

Word Counter

Estimate reading time, speaking time, page count, and character count from your word count. Perfect for writers, students, and presenters.

Screen Size Calculator

Calculate the width, height, and area of any screen from its diagonal size and aspect ratio. Find dimensions for monitors, TVs, and phones.

Typing Speed Calculator

Calculate your typing speed in words per minute (WPM), net WPM, accuracy percentage, and skill level from your typing test results.

Cooking Converter

Convert between cups, tablespoons, teaspoons, milliliters, liters, ounces, grams, and more for cooking and baking recipes.

Download Time Calculator

Free download time calculator. Enter a file size and connection speed to see how long a download takes in hours, minutes and seconds, bits vs bytes handled.

Aspect Ratio Calculator

Free aspect ratio calculator. Simplify any width and height to its lowest ratio with the greatest common divisor, then resize images or video to a new width or height without distortion.

Concrete Calculator

Calculate the amount of concrete needed for your project in cubic feet, cubic yards, and number of 80-pound bags.

Square Footage Calculator

Calculate the square footage of rectangular, circular, or triangular areas and convert to square meters.

Roofing Calculator

Calculate the total roof area, number of roofing squares, and bundles of shingles needed based on roof dimensions and pitch.

Tile Calculator

Calculate how many tiles you need for a room, including grout gaps and waste allowance.

Mulch Calculator

Calculate the amount of mulch needed for your landscaping project in cubic feet, cubic yards, and number of bags.

Gravel Calculator

Calculate the amount of gravel needed in cubic feet, cubic yards, and tons for driveways, paths, and landscaping projects.

Stair Calculator

Calculate the number of steps, riser height, tread depth, and stair angle for any staircase. Includes building code compliance check.

Paint Calculator

Calculate how much paint you need for a room based on wall dimensions, doors, windows, and number of coats.

Fence Calculator

Estimate the number of posts, rails, and pickets needed to build a fence based on length, height, and spacing.

Pool Volume Calculator

Calculate your swimming pool volume in gallons based on shape, dimensions, and depth for chemical treatment planning.

Soil Calculator

Calculate how much soil or topsoil you need in cubic feet, cubic yards, and number of bags for your garden or landscaping project.

Asphalt Calculator

Estimate the volume and weight of hot mix asphalt needed for your driveway, parking lot, or paving project.

Deck Calculator

Estimate decking boards, joists, posts, and screws needed to build a deck based on your dimensions and board size.

Wallpaper Calculator

Calculate how many rolls of wallpaper you need for a room based on dimensions, doors, windows, and roll size.

Drywall Calculator

Calculate how many sheets of drywall you need based on wall dimensions, sheet size, and waste allowance.

Insulation Calculator

Work out how much insulation you need to hit a target R-value: the R-value to add, material thickness in inches, and how many rolls or bags to buy.

Flooring Calculator

Estimate how much flooring to buy for any room. Enter your dimensions, box coverage and a waste factor to get the number of boxes, total square footage, leftover material and full cost for laminate, hardwood, vinyl plank or tile.

Board Foot Calculator

Calculate board feet and cost for lumber from thickness, width, length and quantity. One board foot equals 144 cubic inches of wood, the volume measure hardwood is priced by.

Brick Calculator

Work out how many bricks and mortar bags your wall needs. Enter the wall size and brick type for an instant count, a materials breakdown and a comparison across every common brick size.

Excavation Calculator

Work out excavation and dirt volume for any dig: bank (in-ground) cubic yards, cubic feet, loose haul-away volume after swell, the number of truckloads, and an approximate weight in tons. Enter length, width, and depth in inches or feet.

Centimeters to Inches Converter

Convert centimeters to inches instantly. Centimeters to Inches Converter with full conversion table and reference values.

Inches to Centimeters Converter

Convert inches to centimeters instantly. Inches to Centimeters Converter with full conversion table and reference values.

Kilograms to Pounds Converter

Convert kilograms to pounds instantly. Kilograms to Pounds Converter with full conversion table and reference values.

Pounds to Kilograms Converter

Convert pounds to kilograms instantly. Pounds to Kilograms Converter with full conversion table and reference values.

Meters to Feet Converter

Convert meters to feet instantly. Meters to Feet Converter with full conversion table and reference values.

Feet to Meters Converter

Convert feet to meters instantly. Feet to Meters Converter with full conversion table and reference values.

Celsius to Fahrenheit Converter

Convert Celsius to Fahrenheit instantly. Celsius to Fahrenheit Converter with full conversion table and reference values.

Fahrenheit to Celsius Converter

Convert Fahrenheit to Celsius instantly. Fahrenheit to Celsius Converter with full conversion table and reference values.

Miles to Kilometers Converter

Convert miles to kilometers instantly. Miles to Kilometers Converter with full conversion table and reference values.

Kilometers to Miles Converter

Convert kilometers to miles instantly. Kilometers to Miles Converter with full conversion table and reference values.

Liters to Gallons Converter

Convert liters to US gallons instantly. Liters to Gallons Converter with full conversion table and reference values.

Gallons to Liters Converter

Convert US gallons to liters instantly. Gallons to Liters Converter with full conversion table and reference values.

Ounces to Grams Converter

Convert ounces to grams instantly. Ounces to Grams Converter with reference values.

Grams to Ounces Converter

Convert grams to ounces instantly. Grams to Ounces Converter with reference values.

Millimeters to Inches Converter

Convert millimeters to inches instantly. Millimeters to Inches Converter with reference values.

Inches to Millimeters Converter

Convert inches to millimeters instantly. Inches to Millimeters Converter with reference values.

MPH to KPH Converter

Convert miles per hour to kilometers per hour instantly. MPH to KPH Converter with reference values.

KPH to MPH Converter

Convert kilometers per hour to miles per hour instantly. KPH to MPH Converter with reference values.

Milliliters to US Fluid Ounces Converter

Convert milliliters to US fluid ounces instantly. Milliliters to US Fluid Ounces Converter with reference values.

US Fluid Ounces to Milliliters Converter

Convert US fluid ounces to milliliters instantly. US Fluid Ounces to Milliliters Converter with reference values.

Square Meters to Square Feet Converter

Convert square meters to square feet instantly. Square Meters to Square Feet Converter with reference values.

Square Feet to Square Meters Converter

Convert square feet to square meters instantly. Square Feet to Square Meters Converter with reference values.

Acres to Hectares Converter

Convert acres to hectares instantly. Acres to Hectares Converter with reference values.

Hectares to Acres Converter

Convert hectares to acres instantly. Hectares to Acres Converter with reference values.

Watts to Horsepower Converter

Convert watts to horsepower instantly. Watts to Horsepower Converter with reference values.

Horsepower to Watts Converter

Convert horsepower to watts instantly. Horsepower to Watts Converter with reference values.

PSI to Bar Converter

Convert pounds per square inch to bar instantly. PSI to Bar Converter with reference values.

Fuel Cost Calculator

Calculate how much fuel you need and the total cost for any trip based on distance, fuel efficiency, and gas price.

Gas Mileage Calculator

Calculate your actual gas mileage (MPG) based on miles driven and gallons used. Also shows liters per 100km.

Mileage Calculator

Calculate mileage reimbursement based on miles driven and the IRS standard mileage rate.

Speed Calculator

Calculate speed from distance and time, with results in both miles per hour and kilometers per hour.

Tire Size Calculator

Calculate overall tire diameter, circumference, and revolutions per mile from tire width, aspect ratio, and wheel diameter.

Horsepower Calculator

Calculate engine horsepower from torque and RPM. Also shows kilowatts and metric horsepower equivalents.

Engine Horsepower Calculator

Estimate engine horsepower and torque from displacement, RPM, volumetric efficiency, and aspiration type (NA, turbo, supercharged).

Car Affordability Calculator

Find out how much car you can afford from your monthly budget. Work backward to the vehicle price, max loan, total interest and out-the-door cost.

EV Charging Cost Calculator

Work out what it costs to charge your electric car at home. Enter battery size, charge level, price per kWh and efficiency to see cost, kWh and gas savings.

Density Calculator

Calculate the density of a substance from its mass and volume, with comparisons to common materials.

Molarity Calculator

Calculate the molarity (molar concentration) of a solution from the number of moles and volume in liters.

Wind Chill Calculator

Calculate the wind chill temperature and frostbite risk time based on air temperature and wind speed.

Heat Index Calculator

Calculate the heat index (feels-like temperature) from air temperature and relative humidity, with danger level assessment.

Dew Point Calculator

Calculate the dew point temperature from air temperature and relative humidity, with comfort level assessment.

Force Calculator

Calculate force, mass, or acceleration using Newton's second law (F = ma) with unit conversions to lbf, dynes, and kN.

Pressure Calculator

Calculate pressure, force, or area using the formula P = F/A with conversions to psi, bar, atm, kPa, and mmHg.

Molecular Weight Calculator

Look up the molecular weight, formula, and composition of common molecules including water, CO2, glucose, ethanol, and more.

Height Calculator

Predict a child's adult height using the mid-parent method based on current age, sex, and parents' heights.

Mass Calculator

Calculate mass, density, or volume using the formula m = density x volume. Solve for any variable and see results in multiple units.

Weight on Planets Calculator

Discover how much you would weigh on every planet in the solar system, the Moon, and Pluto based on surface gravity.

Velocity Calculator

Calculate velocity from distance and time, with conversions to km/h and mph.

Acceleration Calculator

Calculate acceleration from the change in velocity over time.

Kinetic Energy Calculator

Calculate the kinetic energy of a moving object using KE = 0.5 x m x v^2.

Momentum Calculator

Calculate the linear momentum of an object using p = m x v.

Work Calculator

Calculate physical work done by a force using W = F x d x cos(theta).

Potential Energy Calculator

Calculate gravitational potential energy using PE = m x g x h.

Power Calculator

Calculate physical power, the rate of doing work, using P = W / t, with conversions to kW and HP.

pH Calculator

Free pH calculator: enter pH, pOH, hydrogen or hydroxide concentration and get the other three plus the acidic, neutral or basic classification at 25 C.

Projectile Motion Calculator

Find the range, max height, time of flight and landing speed of a launched object from its speed, angle, starting height and gravity.

Voltage Drop Calculator

Calculate voltage drop across a wire run based on source voltage, current, wire length, and wire gauge.

Ohm's Law Calculator

Calculate voltage, current, resistance, or power using Ohm's Law. Enter any two known values to find the others.

Electricity Calculator

Calculate the electricity cost of running any appliance based on wattage, usage hours, and your electricity rate.

BTU Calculator

Calculate the BTU (British Thermal Units) needed to heat or cool a room based on size, insulation, and sun exposure.

Resistor Color Code Calculator

Decode 4-band resistor color codes to find the resistance value and tolerance range.

Conduit Fill Calculator

Check NEC conduit fill for EMT, PVC Schedule 40, and rigid metal conduit. See how many THHN/THWN conductors fit under NEC Chapter 9, Table 1.

Wire Size Calculator

Find the minimum copper or aluminum wire size for a given load using the NEC Table 310.16 ampacity values, with the 240.4(D) small-conductor rule applied.

Box Fill Calculator

Calculate the required electrical box volume under NEC 314.16. Counts conductors, devices, clamps, and grounds to tell you if your box is large enough.

Ground Wire Size Calculator

Find the minimum equipment grounding conductor size from the overcurrent device rating using NEC Table 250.122, for copper or aluminum.

Motor FLC Calculator

Look up three-phase motor full-load current from NEC Table 430.250, plus the 125 percent conductor ampacity and 250 percent maximum breaker size.

Dwelling Load Calculator

Size a single-family dwelling electrical service using the NEC standard calculation method (Article 220, Part III), with the Table 220.42 lighting demand factors, Table 220.55 range demand, and the noncoincident heating and cooling rule.

Service Load Calculator

Size a one-family dwelling service the fast way using the NEC optional calculation method (220.82): 100 percent of the first 10 kVA of general load plus 40 percent of the rest, then the largest heating or cooling load.