Volume Calculator
Box, sphere, cylinder, cone and pyramid volumes โ litres included.
About this calculator
Pick a solid โ box, cube, sphere, cylinder, cone, pyramid โ enter its measurements, read the volume with its formula, plus the litre conversion for both centimetre and metre inputs, since that's the step everyone fumbles.
The one-third theorem and other useful facts
The elegant pattern in the formulas: a cone is exactly one-third of its enclosing cylinder, a pyramid one-third of its box โ Archimedes-era results that feel wrong until you see them poured (fill a cone with water three times and it exactly fills the cylinder). The sphere's 4/3 ฯrยณ was Archimedes' own favourite; he had the sphere-in-cylinder inscribed on his tomb. Practical corner: volumes scale with the CUBE of size, so doubling a tank's dimensions gives eight times the water โ the reason big aquariums and big concrete orders surprise people. And the litre bridge: 1,000 cmยณ = 1 L, 1 mยณ = 1,000 L. Flat shapes are the area calculator's department; multiply its answer by a depth and you're back here for concrete, soil and water.
Frequently asked questions
How many litres is my tank?
Measure in cm, multiply length ร width ร height, divide by 1,000: a 60 ร 30 ร 35 cm tank is 63,000 cmยณ = 63 litres. The calculator does the division automatically.
What's the volume of a cylinder?
ฯrยฒ ร height โ the circle's area extruded. Measure the diameter across and halve it for r; that's the classic mistake.
Why is a cone exactly a third of a cylinder?
It's a theorem (provable with calculus or clever slicing): any cone or pyramid holds one-third of the prism with the same base and height. Pour water three times and see.
How much concrete do I need for a slab?
Area ร depth: a 4 m ร 3 m slab at 10 cm deep is 12 ร 0.1 = 1.2 mยณ. Order 5-10% extra for spillage and uneven ground.