Volume Calculator – Litres, Gallons, Cubic Feet & m³

Volume Calculator

Volume is length × width × height for a box, π × r^2 × h for a cylinder and 4/3 × π × r^3 for a sphere, so a 50 × 30 × 40 cm box holds 60,000 cm³, or 60 L. The calculator converts to US gallons and cubic feet and can find the liquid in a partly filled horizontal tank.

By the Calculators With Steps team · Updated November 10, 2026 · How we check our math

Unit	Volume
Cubic centimetres (cm³ = mL)	60,000
Litres (L)	60
Cubic metres (m³)	0.06
Cubic inches (in³)	3,661.4246
Cubic feet (ft³)	2.1189
Cubic yards (yd³)	0.078477
US gallons	15.8503
Imperial (UK) gallons	13.1982

Unit

Volume

Cubic centimetres (cm³ = mL)

60,000

Litres (L)

Cubic metres (m³)

0.06

Cubic inches (in³)

3,661.4246

Cubic feet (ft³)

2.1189

Cubic yards (yd³)

0.078477

US gallons

15.8503

Imperial (UK) gallons

13.1982

How to use the volume calculator

Choose the shape: box, cube, cylinder, sphere, hemisphere, cone, pyramid, triangular prism, capsule or a partly filled horizontal tank.
Choose the length unit you measured in. Every dimension must use that unit.
Enter the dimensions. Where a shape needs a radius, use half the diameter.

The result shows the volume in your unit cubed, then litres, US gallons, cubic feet and cubic metres, plus the surface area for most shapes. A table underneath converts the answer to every common unit, including cubic yards and imperial gallons.

Volume formulas

Shape	Volume formula	Example (cm)	Volume
Rectangular prism (box)	V = l × w × h	50 × 30 × 40	60,000 cm³
Cube	V = s³	s = 10	1,000 cm³
Cylinder	V = πr²h	r = 10, h = 30	9,424.778 cm³
Sphere	V = (4/3)πr³	r = 10	4,188.7902 cm³
Hemisphere	V = (2/3)πr³	r = 10	2,094.3951 cm³
Cone	V = (1/3)πr²h	r = 10, h = 30	3,141.5927 cm³
Pyramid (rectangular base)	V = (l × w × h) ÷ 3	50 × 30 × 40	20,000 cm³
Triangular prism	V = ½ × b × h × length	6, 4, 20	240 cm³
Capsule	V = πr²a + (4/3)πr³	r = 10, a = 20	10,471.98 cm³

Notice the patterns. A cone is one third of the cylinder that fits around it, and a pyramid is one third of the matching box. A capsule is a cylinder with a sphere split across its two ends.

Worked examples

An aquarium. A tank measures 50 cm × 30 cm × 40 cm. V = 50 × 30 × 40 = 60,000 cm³. Since 1 litre = 1,000 cm³, that is 60 litres, or about 15.8503 US gallons. In practice the water level sits a little below the rim, so the usable volume is slightly less.

A water tank in feet. A rectangular tank is 4 ft × 2 ft × 1.5 ft. V = 12 ft³, which is about 339.8022 litres or 89.7662 US gallons.

A cylindrical pot. A pot has a 10 cm radius and is 30 cm tall. V = π × 10² × 30 ≈ 9,424.778 cm³, or about 9.4248 litres.

Litres, gallons and cubic units

Unit	Equals
1 litre	1,000 cm³ (1,000 mL)
1 cubic metre	1,000 litres
1 US gallon	3.785411784 litres (231 in³)
1 imperial (UK) gallon	4.54609 litres
1 cubic foot	28.316846592 litres, about 7.48052 US gallons
1 cubic yard	27 cubic feet, about 764.5549 litres

US and imperial gallons are different sizes, so check which one a product or regulation uses. Cubic yards are the usual unit for ordering concrete, soil and mulch in the US; the concrete calculator handles slabs, footings and bags.

Partly filled horizontal tanks

Oil tanks, diesel tanks and many water tanks lie on their side, so the liquid volume is not simply proportional to the depth. The calculator uses the circular-segment formula:

V = L × [r² × acos((r − h) ÷ r) − (r − h) × √(2rh − h²)]

where r is the tank radius, L its length and h the liquid depth. For a tank 120 cm across and 300 cm long with 45 cm of liquid, that gives about 1,162.139 litres. The full tank holds about 3,392.9201 litres, so it is 34.3% full even though the depth is 37.5% of the height. Near the bottom and top of a round tank, each centimetre of depth holds less liquid than it does in the middle.

Tips for accurate volumes

Radius, not diameter. The most common mistake is putting the diameter into πr²h, which makes the answer four times too big.
Use inside measurements for containers. Wall thickness can take several litres off a small tank.
Do not mix units. Convert everything first with the unit converter, or the answer will be meaningless.
Need the area of one face? The area calculator covers rectangles, circles, triangles and more.

Volume Calculator: frequently asked questions

How do you calculate the volume of a box?

Multiply length × width × height. A box or aquarium measuring 50 cm × 30 cm × 40 cm holds 60,000 cm³, which is 60 litres or about 15.85 US gallons.

How do you calculate the volume of a cylinder?

Use V = πr²h, where r is the radius and h is the height. A cylinder with a 10 cm radius and 30 cm height holds about 9,424.78 cm³, or roughly 9.42 litres.

What is the formula for the volume of a sphere?

V = (4/3)πr³. A ball with a 10 cm radius has a volume of about 4,188.79 cm³, which is about 4.19 litres.

How do you calculate the volume of a cone?

V = (1/3)πr²h, which is exactly one third of a cylinder with the same base and height. A cone with a 10 cm radius and 30 cm height has a volume of about 3,141.59 cm³.

How do I convert cubic feet to gallons?

One cubic foot holds about 7.48052 US gallons (28.3168 litres). A 4 ft × 2 ft × 1.5 ft tank is 12 cubic feet, so it holds about 89.77 US gallons.

How many litres are in a cubic metre?

There are exactly 1,000 litres in a cubic metre, and one litre is 1,000 cm³ (1,000 mL). A 1 m × 1 m × 1 m tank therefore holds 1,000 litres.

How do I work out how much liquid is in a horizontal tank?

Choose the horizontal cylindrical tank option and enter the diameter, length and liquid depth. A tank 120 cm across and 300 cm long with 45 cm of liquid holds about 1,162 litres, which is 34.3% of its 3,393-litre capacity.

How do you find the volume of a pyramid?

Multiply the base area by the height and divide by 3. A pyramid with a 50 cm × 30 cm base and a 40 cm height has a volume of 20,000 cm³, or 20 litres.