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Volume Calculator

Find the volume of a cube, box, cylinder, sphere, cone, pyramid or hemisphere, with liters, gallons and the steps.

Results

ItemValue

Steps

StepWorking
Enter all sizes in the same unit. For a diameter, divide it by 2 to get the radius. Answers are rounded to 4 decimal places.

Quick Answer

Volume is the space inside a 3D shape, in cubic units. A box is length × width × height, so 5 × 4 × 10 ft = 200 ft³. A cylinder is π × r² × h, so a radius of 3 ft and a height of 10 ft gives about 282.74 ft³, or 2,115 US gallons.

Last updated: 2 November 2026 ·How we calculate this: standard volume formulas

Table of Contents

How This Volume Calculator Works

Pick a shape and a unit, then enter its sizes. The calculator shows the volume in cubic units, plus liters, US gallons, cubic feet and cubic meters, with the formula and working.

Quick explanation: volume = how much space a shape holds, in cubic units such as ft³.

  • Same unit: enter every size in the unit you choose.
  • Radius: half the diameter.
  • Converting: use our Volume Conversion Calculator for other units.

How to Use the Volume Calculator

  1. Choose the shape that matches your object.
  2. Choose the unit you measured in.
  3. Enter the sizes shown for that shape, such as radius and height for a cylinder.
  4. Press Calculate.
  5. Read the volume in cubic units, liters, US gallons, cubic feet and cubic meters.

Core Formulas

  • Cube: V = s³
  • Rectangular box: V = l × w × h
  • Cylinder: V = π × r² × h
  • Sphere: V = 4/3 × π × r³
  • Cone: V = π × r² × h ÷ 3
  • Rectangular pyramid: V = l × w × h ÷ 3
  • Hemisphere: V = 2/3 × π × r³

Key Terms

  • Volume: the amount of space inside a 3D shape.
  • Cubic unit: a cube with sides of 1 unit, such as 1 ft³.
  • Radius: the distance from the center of a circle to its edge.
  • Diameter: the distance across a circle through its center, twice the radius.
  • Base: the face a shape stands on, such as the circle of a cylinder.
  • Capacity: how much a container can hold, often given in liters or gallons.

Worked Example

A ball has a radius of 5 cm.

  • V = 4/3 × π × 5³
  • V = 4/3 × π × 125 = 523.5988 cm³
  • That is about 0.52 liters

Real-Life Examples

  • A fish tank: a box 36 in long, 12 in wide and 16 in high holds 6,912 in³, which is about 29.9 US gallons.
  • A water tank: a cylinder with a 2 ft radius and 5 ft height holds about 62.8 ft³, or about 470 US gallons.
  • A planter: a cone-shaped pot with a 6 in radius and 12 in depth holds about 452 in³, which is about 7.4 liters of soil.
  • A ball: a basketball with a radius of about 4.7 in holds about 435 in³ of air.

Volume vs Surface Area

  • Volume: the space inside a shape, in cubic units such as ft³. Use it for how much a container holds.
  • Surface area: the total area of the outside, in square units such as ft². Use it for paint or wrapping.
  • Scaling: doubling every size multiplies surface area by 4 and volume by 8.

Volume Unit Conversions

UnitEquals
1 cubic foot1,728 in³, about 7.48 US gallons or 28.32 liters
1 cubic yard27 ft³, about 201.97 US gallons or 764.55 liters
1 cubic meter1,000 liters, about 264.17 US gallons or 35.31 ft³
1 US gallon231 in³, about 3.785 liters
1 liter1,000 cm³, about 61.02 in³

Tips for Accurate Results

  • Measure inside: for tanks and containers, use inside sizes.
  • Mixed units: change inches to feet first (divide by 12).
  • Odd shapes: split them into simple shapes and add the volumes.

Common Mistakes to Avoid

  • Using diameter instead of radius. Halve the diameter first.
  • Mixing units. All sizes must be in the same unit.
  • Forgetting the ÷ 3. Cones and pyramids hold one third of a cylinder or box with the same base and height.
  • Measuring outside sizes for a container. Wall thickness reduces what it can hold.
  • Confusing US and UK gallons. This calculator uses US gallons.

Frequently Asked Questions

Use the formula for the shape. For a box, multiply length, width and height.

Multiply π by the radius squared, then by the height.

One cubic foot holds about 7.48 US gallons.

Area measures a flat surface in square units. Volume measures space in cubic units.

Divide the diameter by 2 to get the radius, then use the formula.

There are exactly 1,000 liters in a cubic meter.

For a rectangular pool, multiply length × width × average depth. For a round pool, use the cylinder shape with the radius and average depth.

Divide cubic inches by 231 to get US gallons. For example, 6,912 in³ is about 29.9 gallons.

Put it in water and measure how much the water level rises. The rise in volume equals the object’s volume.

About 282.74 ft³, or about 2,115 US gallons.

References & Sources

SourceUsed ForLink
Wikipedia, Volume Volume formulas for common shapes. https://en.wikipedia.org/wiki/Volume
NIST, Unit conversion US customary and metric volume units. https://www.nist.gov/pml/owm/metric-si/unit-conversion