Volume formulas for common shapes
The most frequently used volume formulas all hinge on squaring or cubing a dimension — the kind of power an exponent calculator evaluates instantly:
- Cube: V = s³ (a 2-foot cube holds 8 cubic feet or 59.8 gallons).
- Rectangular prism: V = l × w × h.
- Cylinder: V = πr²h — a 4-foot diameter, 3-foot tall cylindrical tank holds π(2²)(3) = 37.7 ft³ = 282 gallons.
- Sphere: V = (4/3)πr³.
- Cone: V = (1/3)πr²h — exactly one-third of a cylinder with the same base and height.
- Pyramid: V = (1/3) × base area × h.
For irregular shapes, break them into simpler components, calculate each separately, and sum the results. A swimming pool with a shallow end (3ft) and deep end (8ft) can be approximated as a rectangular prism with average depth: V = length × width × (3+8)/2.