Volume Calculator

Calculate the volume of common 3D shapes: cube, sphere, cylinder, cone, rectangular prism, and more.

Shape

Unit

Length

Width

Height

Volume

400

cubic feet (ft³)

Volume	400 ft³
Surface Area	340 ft²
Formula used	V = l × w × h = 10 × 5 × 8

Volume Conversions

ft³400

in³691,200

yd³14.8148

m³11.3267

gallons2,992.208

liters11,326.72

How to Use the Volume Calculator

Select the shape that best matches the object: cube, rectangular prism (box), sphere, cylinder, cone, triangular prism, square pyramid, or ellipsoid.
Choose your unit. Select feet, inches, yards, meters, centimeters, or millimeters. All dimensions must be in the same unit. The output will be in cubic units of that type.
Enter the dimensions. The required fields update for each shape. For a sphere, only the radius is needed. For a cylinder, you need radius and height. Use the perpendicular height for cones and pyramids, not the slant height.
Read the results. The panel shows volume, surface area, the formula used, and automatic conversions to ft³, gallons, and liters.

Example: a cylindrical water tank with radius 3 feet and height 8 feet has volume = π × 3² × 8 = 226.19 ft³ = 1,692 gallons.

Volume Formulas for Common Shapes

Shape	Volume Formula	Surface Area
Cube	V = s³	6s²
Rectangular Prism	V = l × w × h	2(lw + lh + wh)
Sphere	V = (4/3)πr³	4πr²
Cylinder	V = πr²h	2πr(r + h)
Cone	V = (1/3)πr²h	πr(r + slant)
Square Pyramid	V = (1/3)b²h	b² + 2b√((b/2)² + h²)
Triangular Prism	V = (1/2)bhl	base perimeter × l + 2 × triangle area
Ellipsoid	V = (4/3)πabc	approximation

Key volume conversions: 1 ft³ = 7.48 US gallons = 28.32 liters. 1 m³ = 1,000 liters = 264.2 US gallons. 1 liter = 0.264 gallons = 61.02 in³. 1 US gallon = 231 in³ = 3.785 liters.

Frequently Asked Questions

Volume of a rectangular prism = length × width × height. A room 15 ft long, 12 ft wide, and 9 ft tall has volume = 15 × 12 × 9 = 1,620 cubic feet. For HVAC sizing, this matters: a 1,620 ft³ room needs different air circulation than a 3,000 ft³ space. To find how many gallons a tank holds, multiply cubic feet by 7.48. A 4 ft × 2 ft × 2 ft tank = 16 ft³ = 119.7 gallons.

Related Calculators

Area Calculator

Calculate the area of circles, rectangles, triangles, trapezoids, and other shapes.

Triangle Calculator

Calculate the area, perimeter, angles, and sides of any triangle.

Pythagorean Theorem Calculator

Find any side of a right triangle using the Pythagorean theorem (a² + b² = c²).