How this cylinder volume calculator works
A cylinder is a solid with two parallel circular ends joined by a curved side. Its volume is the area of one circular base multiplied by the height of the cylinder. Because the base area is πr², the volume formula is V = πr²h, where r is the base radius and h is the height. The answer comes out in cubic units — cubic centimetres, cubic metres, cubic inches or cubic feet, depending on the unit you pick.
If you only know the diameter, switch the toggle to "Diameter" and the calculator halves it to find the radius first (r = d ÷ 2). It then also reports the lateral surface area (the curved side, 2πrh), the total surface area (the side plus both circular ends, 2πr² + 2πrh), and the base circumference (2πr). For tanks and containers it converts the volume to liters and US gallons so you can read off capacity directly.
Reference note: calculations use π ≈ 3.14159265. Liters are derived by converting the volume to cubic centimetres and dividing by 1000 (1 L = 1000 cm³); US gallons divide liters by 3.785411784. Measure the interior of a container so wall thickness is not counted.
Frequently asked questions
- What is the volume of a cylinder?
- The volume of a cylinder is the space it encloses, found by multiplying the area of its circular base by its height: V = πr²h, where r is the base radius and h is the height. The result is in cubic units, such as cubic centimetres or cubic feet.
- What is the formula for the volume of a cylinder?
- The formula is V = πr²h. Square the radius, multiply by pi (about 3.14159), then multiply by the height. For example, a cylinder with radius 3 and height 10 has a volume of π × 3² × 10 ≈ 282.7 cubic units.
- How do I find volume from the diameter?
- Halve the diameter to get the radius (r = d ÷ 2), then use V = πr²h. Equivalently you can use V = π(d²/4)h. This calculator has a diameter toggle that does the conversion for you automatically.
- What is the surface area of a cylinder?
- The lateral (side) surface area is 2πrh. The total surface area adds the two circular ends: 2πr² + 2πrh. These describe the material needed to wrap or build the cylinder, in square units.
- How many liters or gallons does a cylinder hold?
- Compute the volume, convert it to cubic centimetres, then divide by 1000 to get liters (1 L = 1000 cm³). For US gallons, divide the liters by 3.785411784. This calculator shows both capacities automatically for any unit you choose.
- How do I measure a cylindrical tank?
- Measure the inside diameter (or radius) of the circular base and the inside height of the liquid space, using the same unit for both. Enter them here to get the volume and the capacity in liters and gallons. Measure the interior, not the outside, so wall thickness is not counted.