Volume Calculator
Calculate the volume of common 3D shapes — cube, box, cylinder, sphere, cone, and triangular prism — in any of the five supported units.
What this calculator does
This is a pure geometry calculator: it takes dimensions and returns volume. It does not estimate materials, costs, or weights. For those, link out to the construction calculators in the related list.
Formula
Cube: V = s³
Rectangular prism (box): V = l × w × h
Cylinder: V = π × r² × h
Sphere: V = (4 ÷ 3) × π × r³
Cone: V = (1 ÷ 3) × π × r² × h
Triangular prism: V = ½ × b × h × L
Variable definitions
s— Side length of a cube.l, w, h— Length, width, and height of a rectangular prism.r— Radius of a circular cross-section (half the diameter).b, L— Triangle base, and the length the prism extends.
Step-by-step calculation
- Select the shape that matches your object.
- Enter each dimension in your preferred unit.
- Dimensions are converted to meters and the formula is applied.
- The result in m³ is converted to in³, ft³, yd³, cm³, and m³ for display.
Worked example
A cylinder with radius 6 in and height 12 in:
V = π × 6² × 12 = π × 36 × 12 = 1357.17 in³ (≈ 0.7854 ft³, ≈ 0.0222 m³).
How to use this calculator
- Choose the shape.
- Type each dimension. Mix units? Convert one dimension first, or set them all to the same unit.
- Pick rounding precision and copy or share the result with all cubic units.
Common mistakes
- Diameter vs radius: for cylinders, spheres, and cones, the input is radius. Half the diameter first.
- Mismatched units: if some dimensions are in inches and others in feet, the formula gives a meaningless number. Use the same unit, or convert.
- Confusing area with volume: a slab's "square footage" is area. Multiply by the thickness in feet to get cubic feet, or use the Concrete Slab Calculator.
Frequently asked questions
›Which shapes does this calculator support?
Cube, rectangular prism (box), cylinder, sphere, cone, and triangular prism. Pick the shape and the form swaps to show only the dimensions that shape needs.
›Which units can I use?
Inches, feet, yards, centimeters, and meters. All dimensions are converted to meters internally, the volume is computed in m³, then converted to in³, ft³, yd³, cm³, and m³ for display.
›Why is the answer slightly different from a hand calculation?
This calculator uses full double-precision π (≈ 3.14159265358979). Hand calculations often use 3.14 or 3.1416 and will differ in the last few digits.
›Does the cylinder/cone radius mean radius or diameter?
Radius. If you have the diameter, divide by 2 first. The form labels each input so the meaning is unambiguous.
›Is this the right tool for concrete or gravel?
No. This is a general geometry calculator. For ready-mix concrete with bag counts and waste factor, use the Concrete or Concrete Slab Calculator. For tonnage and coverage of crushed stone, use the Gravel Calculator.
›How is the triangular prism defined?
Volume = ½ × base × height × length, where base and height describe the triangular cross-section and length is the depth along the prism.
›How is rounding handled?
All math uses full precision; only displayed volumes are rounded to the decimal places you choose.
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