Find the volume of any shape.
Pick a 3D shape, enter its dimensions, and see the volume, surface area, and how much liquid it would hold in gallons and liters. Everything updates as you type.
Your shape
Length, width and height of the box.
What the numbers mean
Capacity scorecard
How volume grows with size
Volume scales with the cube of linear size. Double every dimension and the volume grows eight times, not two.
| Scale | Volume (ft³) | vs current | Gallons | Liters |
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Volume, explained
Volume Formulas for 3D Shapes
Cube: V = s³. Sphere: V = 4/3 × πr³. Cylinder: V = πr²h. Cone: V = 1/3 × πr²h. Rectangular Prism: V = l × w × h. A cone is exactly 1/3 the volume of a cylinder with the same base and height, which is a useful relationship to remember.
Understanding Volume Units
Volume is measured in cubic units, cubic inches (in³), cubic feet (ft³), cubic meters (m³), liters, gallons, etc. Key conversions: 1 ft³ = 1,728 in³, 1 m³ = 1,000 liters, 1 gallon ≈ 231 in³, 1 liter = 1,000 cm³. Always use consistent units in calculations.
Volume vs Capacity
Volume measures how much 3D space an object occupies. Capacity measures how much a container can hold. They are related but use different units: volume uses cubic units (m³, ft³), capacity uses liquid units (liters, gallons). In practice, they are often used interchangeably.
Real-World Volume Calculations
Volume calculations are needed for swimming pools (water capacity), shipping containers, concrete work, aquariums, storage tanks, cooking and baking, and packaging design. Knowing how to calculate volume helps estimate materials, costs, and capacities accurately.
Common questions
How do I calculate volume in gallons?
Calculate volume in cubic inches, then divide by 231 to convert to US gallons. Alternatively, calculate in cubic feet and multiply by 7.481. For metric, calculate in cubic centimeters and divide by 1,000 for liters.
What is the relationship between a cylinder and a cone?
A cone has exactly 1/3 the volume of a cylinder with the same base radius and height. This means three cones can fill one cylinder of equal dimensions.
How much water does a cylindrical tank hold?
Calculate V = πr²h in cubic inches, then divide by 231 for US gallons or by 61.024 for liters. For example, a tank 24 inches in diameter and 48 inches tall holds about 94 gallons.
What is the volume of a hemisphere?
A hemisphere is half a sphere: V = 2/3 × πr³. For a dome or bowl shape, use this formula with the radius of the curved surface.
Estimates for planning only. Capacity in gallons and liters assumes your dimensions are in feet and the container holds liquid with no wall thickness. For exact tank or pool figures, verify with the manufacturer.