Volume Calculator
Calculate the volume of common 3D shapes including cube, sphere, cylinder, cone and pyramid with results in cubic cm, m and litres
Formula: V = a³
Cubic Centimeters
1000.00 cm³
Cubic Meters
0.001000 m³
Liters
1.00 L
Volume Formulas for the Six Standard Shapes
Cube: a³, where a is the side length. Rectangular prism (a regular box): l × w × h. Sphere: (4/3)πr³. Cylinder: πr²h. Cone: (1/3)πr²h. Pyramid: (1/3) × base area × h. The pattern worth noticing: cones are always one-third of the cylinder they would fit inside, and pyramids are always one-third of the prism they would fit inside. Spheres are two-thirds of the cylinder that surrounds them.
Real measurements rarely come in neat units. The calculator works in centimetres, then converts to cubic metres and litres automatically (1 litre = 1,000 cm³ = 0.001 m³). For an aquarium that is 80 cm × 35 cm × 40 cm, that is 112,000 cm³ = 112 litres of water capacity, before you subtract for substrate and decoration.
Aquariums, Pools, and Pots
Aquarium owners want litres so they can pick the right filter and heater. A 60 cm × 30 cm × 36 cm tank is 64,800 cm³ = 64.8 litres. Subtract about 10% for substrate and rocks, so plan filtration for around 58 litres of actual water. Pool owners want cubic metres for chemical dosing; a 3 m × 6 m rectangular pool with an average depth of 1.4 m is 25.2 m³, which gives you a starting figure for chlorine and pH adjusters.
Cylindrical pots, planters, and water tanks are the most common non-rectangular case. Volume = π × r² × h. A 30 cm diameter pot (radius 15 cm) that is 25 cm tall is π × 15² × 25 = 17,671 cm³ = 17.7 litres of compost. For shipping or storage in feet rather than centimetres, [Cubic Feet Calculator](/cubic-feet-calculator) is the one to use.
Volume Formulas at a Glance
| Shape | Formula | Example (10 cm sides/radius) |
|---|---|---|
| Cube | a³ | 1,000 cm³ |
| Sphere | (4/3)πr³ | 4,189 cm³ |
| Cylinder | πr²h | 3,142 cm³ |
| Cone | (1/3)πr²h | 1,047 cm³ |
| Pyramid | (1/3) × b × h | depends on base |
| Prism | l × w × h | 1,000 cm³ |
Frequently Asked Questions
How many litres in a cubic metre?
Exactly 1,000. So a 2 m³ water tank holds 2,000 litres. Useful for sizing rainwater butts, hot tubs, and koi ponds. Going the other way: 1 litre = 0.001 m³ = 1,000 cm³.
Why is a cone exactly one-third of a cylinder?
Geometrically, you can fit exactly three cones inside a cylinder of the same base and height; this can be demonstrated with water, sand, or rice in physical models. The same one-third relationship holds between any pyramid and the prism that surrounds it. It comes out of the calculus of integration, but the intuition is the simple sand-pouring experiment.
How do I find the volume of an irregular shape?
If it is solid and small enough, use water displacement: drop it into a measuring jug and read off the rise in volume (1 ml = 1 cm³). If it is too big, decompose it into shapes you can calculate: a stepped pond is two rectangular prisms stacked; an L-shaped room split into two rectangles, then multiplied by ceiling height.
What is the difference between volume and capacity?
Volume is the space something occupies (in cm³ or m³). Capacity is how much liquid it can hold (in litres or millilitres). For containers they are essentially the same thing; for solid objects only volume applies. 1 litre of capacity equals 1,000 cm³ of internal volume.