Volume Calculator
Pick the shape, enter its dimensions in feet and inches (or meters), and read the volume in every unit at once — cubic feet, cubic yards, US gallons, cubic meters, and liters, all from exact conversion factors.
Shape and dimensions
Example: a 4 × 3 × 2 ft box holds 24 cu ft = 0.8889 cu yd.
Pure geometry for quantity planning — whether a tank, footing, or container is structurally adequate for its contents is a question for a qualified engineer or contractor.
Four formulas, one exact pipeline
Every shape reduces to cubic feet first. The box is
V = L × W × H: 4 × 3 × 2 ft = 24 cu ft = 0.8889 cu yd. The cylinder is V = πr²h: a 3 ft radius by
5 ft tall gives 141.37 cu ft. The sphere is V = 4/3 πr³ (3 ft radius → 113.1 cu ft), and the cone is V = πr²h ÷ 3 — one third
of its cylinder, 47.12 cu ft for the same 3 × 5 ft dimensions. Every
figure in this paragraph is computed at build time by the same engine behind the form.
Why every conversion here is exact
Cubic feet to cubic yards divides by 27 — a yard is 3 feet, cubed. Cubic feet to cubic meters multiplies by 0.028316846592, the exact cube of the 0.3048 m international foot. Liters are 0.001 m³ by definition. And US gallons come from the gallon's own definition of exactly 231 cubic inches: one cubic foot is 1,728 cubic inches, so the factor is the exact fraction 1728/231 ≈ 7.4805 gallons per cubic foot. The only non-rational number in the whole chain is π itself.
From geometry to a shopping list
This page measures; it does not order. When the volume is destined to be filled with something, hand it to the estimator that knows how that material is sold: the concrete slab calculator for pours with waste and quarter-yard ordering, the gravel calculator or topsoil calculator for bulk material by the whole yard, and the square footage calculator when the job starts from a floor plan rather than a solid.
Frequently asked questions
Which formula does each shape use?
Box: length × width × height. Cylinder: π × radius² × height. Sphere: 4/3 × π × radius³. Cone: π × radius² × height ÷ 3 — exactly one third of the matching cylinder. All dimensions are in feet, and the result starts in cubic feet before the exact unit conversions.
I measured the diameter — what do I enter?
Half of it. The radius fields take half the diameter: a 6 ft wide tank has a 3 ft radius. If your measurement lands on an odd inch count, enter the inches in the "+ inches" field and the tool carries them exactly.
Where do the gallon and liter figures come from?
From definitions, not estimates. A US gallon is defined as exactly 231 cubic inches, so a cubic foot (1,728 cubic inches) is exactly 1728/231 ≈ 7.480519 gallons. A liter is exactly 0.001 m³, and a cubic foot is exactly 0.028316846592 m³. No conversion factor on this page is an approximation.
Can I use this for concrete, gravel, or soil quantities?
For the raw geometry, yes — the cubic-yard line is exactly what a supplier needs. But the material tools go further: the concrete slab, gravel, and topsoil calculators add the waste cushion and the whole-unit ordering step this pure measuring tool deliberately leaves out.
Dimensions are computed locally and never leave your device. The exactness rules for every conversion factor are documented on the methodology page.