Volume Calculator: Cubes, Cylinders, Spheres and More

Volume Calculator

Calculate volume and total surface area for common 3D solids, then convert the result to cubic units, liters, and US gallons.

Measurements: use inside dimensions for capacity and outside dimensions for the physical envelope. A capsule uses the straight cylindrical length between its two hemispherical ends.

Volume and surface-area formulas

SolidVolumeTotal surface area
Rectangular prismV = lwhA = 2(lw + lh + wh)
CubeV = s³A = 6s²
CylinderV = πr²hA = 2πr(r + h)
ConeV = πr²h ÷ 3A = πr(r + √(r²+h²))
SphereV = 4πr³ ÷ 3A = 4πr²
HemisphereV = 2πr³ ÷ 3A = 3πr², including the circular base
Square pyramidV = b²h ÷ 3A = b² + 2b√((b÷2)²+h²)
CapsuleV = πr²h + 4πr³ ÷ 3A = 2πrh + 4πr²

Checked examples

Shape and measurementsVolumeSurface area
Rectangular prism: 4 × 3 × 2 m24 m³52 m²
Cube: side 3 m27 m³54 m²
Cylinder: r=2 m, h=5 m20π ≈ 62.8319 m³28π ≈ 87.9646 m²
Cone: r=3 m, h=4 m12π ≈ 37.6991 m³24π ≈ 75.3982 m²
Sphere: r=3 m36π ≈ 113.097 m³36π ≈ 113.097 m²
Hemisphere: r=3 m18π ≈ 56.5487 m³27π ≈ 84.823 m²

How to use this calculator

  1. Select the solid shape.
  2. Choose the unit used for every entered length.
  3. Enter only the dimensions displayed for that shape.
  4. Calculate to obtain volume, total surface area, liters, cubic feet, and US gallons.
  5. Keep full precision for later calculations; round only the final practical result.

Conversions and limits

  • 1 m³ = 1,000 liters = 35.3146667 ft³ ≈ 264.172052 US gallons.
  • Every dimension must be greater than zero and no greater than 10⁹ selected length units.
  • Surface area includes every exposed face; hemisphere area includes its flat circular base.
  • The formulas assume ideal geometric solids and do not subtract wall thickness, openings, internal parts, or freeboard.
  • For buying concrete, soil, gravel, or other materials, use the specialized calculator that includes waste, density, bags, and purchasing units.

Frequently asked questions

Why is volume measured in cubic units?

Volume multiplies three independent lengths. If each length is measured in meters, the product is cubic meters.

Is surface area the same as volume?

No. Surface area measures the outside covering in square units; volume measures the enclosed three-dimensional space in cubic units.

Does cylinder height include the radius?

No. Enter the straight perpendicular distance between the two circular bases.

What length should I enter for a capsule?

Enter the cylindrical middle section only. The calculator adds the two hemispherical ends, which together form one sphere.

Related calculators

Use the Circle Area Calculator for 2D circles, the Square Footage Calculator for floors and rooms, the Pool Volume Calculator for gallons and fill time,, the Concrete Calculator for slabs, bags, and ordering allowance, or the Density Calculator to calculate mass, volume, or density from the other two quantities.