Volume Calculator
Find the volume of a cube, rectangular prism, cylinder, sphere, cone, pyramid or capsule in litres and cubic metres first. Enter dimensions in mm, cm or m and get the result instantly converted to cubic feet and gallons too.
0.7854 m³
0.7854 m³ · 785,398.2 cm³ · 785.4 L · 27.736 ft³ · 1.0273 yd³
207.48 US gal · 172.76 imperial gal (UK/CA/AU).
Standard geometric formulas (V=s³, l·w·h, πr²h, (4/3)πr³, (1/3)πr²h, (1/3)lwh); capsule = cylinder + full sphere. Unit conversions per SI/imperial definitions. How we calculate →
Working out volume in litres and cubic metres
Volume tells you how much space a 3D shape takes up, and in the UK it's usually reported in cubic metres (m³) or litres (L) — 1 m³ is exactly 1,000 litres. A cylindrical water butt with a 0.3 m radius and 1 m height holds π × 0.3² × 1 ≈ 0.2827 m³, which is about 282.7 litres. Enter your own measurements above in mm, cm or m and the calculator returns the volume in every common unit at once.
The formula for each shape
A cube uses V = side³, a rectangular box uses V = length × width × height, a cylinder (a water tank or pipe cross-section) uses V = π r² × height, a sphere uses V = (4/3)π r³, a cone uses V = (1/3)π r² × height, a pyramid with a rectangular base uses V = (1/3) × length × width × height, and a capsule (a cylinder with two rounded ends) adds one full sphere's volume to the cylinder.
Litres, cubic metres and imperial gallons
Everything is calculated internally in cubic metres, then converted instantly to litres, cubic feet and both US and imperial gallons. That matters in the UK because plumbing and tank specs are often quoted in litres while older fittings or American products list US gallons — 1 imperial gallon ≈ 4.546 litres, while 1 US gallon ≈ 3.785 litres, a difference worth checking before you buy a container by gallon size.
Everyday UK uses
Homeowners use this for sizing a cylindrical cold-water tank in litres, working out how much soil a raised bed (a rectangular prism) needs in cubic metres, checking a garden pond's capacity, or converting a manufacturer's cubic-foot spec on an imported appliance into litres. Switch shape and unit above rather than reaching for a separate converter.
Frequently asked questions
How do I work out the volume of a cylindrical tank in litres?
Volume = π × radius² × height, in metres, then multiply by 1,000 to get litres. A tank with a 0.5 m radius and 1.2 m height holds π × 0.5² × 1.2 ≈ 0.9425 m³, or about 942.5 litres. Enter radius and height above to get the exact figure in litres and m³ together.
How many litres are in a cubic metre?
Exactly 1,000 litres make one cubic metre. A 1 m × 1 m × 1 m box therefore holds 1,000 litres — the calculator shows litres alongside m³ automatically so no separate conversion is needed.
What's the difference between an imperial gallon and a US gallon?
An imperial (UK) gallon is about 4.546 litres, while a US gallon is smaller at about 3.785 litres — roughly 20% less. If you're buying a container specified in US gallons, convert to litres first to compare it fairly against a UK-labelled product; this calculator shows both.
How do I calculate the volume of a rectangular raised bed?
Multiply length × width × height in metres. A bed 2 m × 1 m × 0.3 m deep holds 2 × 1 × 0.3 = 0.6 m³ of soil, which is 600 litres. Enter your dimensions in mm, cm or m above and switch straight to whichever unit your supplier quotes soil in.
How much water does a garden pond hold?
For a roughly cylindrical pond, use V = π × radius² × depth; for a rectangular pond use length × width × depth. A round pond 1 m radius and 0.6 m deep holds about 1.885 m³, or 1,885 litres — enter your own dimensions above for an exact figure in litres or m³.
Researched & verified by the Calcuris Data & Research Team. How we build and check our tools →