A space 10 ft long, 8 ft wide and 4 ft high holds 320 cubic feet — 11.85 cubic yards, 2,394 US gallons or 9,061 liters. The calculator above finds the volume and surface area of seven shapes — box, cube, cylinder, sphere, cone, pyramid and triangular prism — and shows the result in every unit you might need.
How the calculator works
Choose the shape, enter its dimensions in feet and inches (or meters), and read the volume in cubic feet, cubic yards, gallons, liters and cubic meters, with the surface area of the shape.
Formulas
| Shape | Volume | Surface |
|---|---|---|
| Box | a × b × c | 2 (ab + ac + bc) |
| Cube | a³ | 6 a² |
| Cylinder | π r² h | 2 π r (r + h) |
| Sphere | 4/3 π r³ | 4 π r² |
| Cone | 1/3 π r² h | π r (r + √(r² + h²)) |
| Pyramid | 1/3 a b h | base + four triangles |
| Triangular prism | ½ a h × L | two triangles + three sides |
Units
A cubic yard is 27 cubic feet — the unit for concrete, gravel and mulch. A cubic foot holds 7.48 US gallons or 28.3 liters; a cubic meter is 35.3 cubic feet. Cones and pyramids hold exactly a third of the box or cylinder around them.
Common mistakes
- Mixing inches and feet. 6 in is 0.5 ft — convert before multiplying, or enter feet and inches directly.
- Diameter for radius. Using the diameter in π r² makes the volume four times too large.
- Cubic yards from square feet. Multiply by the depth in feet first, then divide by 27.
For cylinders and tanks, use the Cylinder Volume Calculator and the Tank Volume Calculator; for concrete, the Concrete Calculator.