Cylinder Volume Calculator
Enter the radius or diameter and the height of a cylinder to get its volume in cubic units, liters and gallons, plus the lateral and total surface area. Add a fill level to see how much liquid a partly full upright tank holds.
For an upright tank partly full of liquid
How to use the Cylinder Volume Calculator
- Choose radius or diameter, whichever you measured.
- Enter the size and the height (or length, for a pipe or a tank on its side).
- Pick the unit you measured in.
- Optionally enter a fill level for an upright tank that is partly full.
- Read the volume in your units, liters and gallons, and check the conversion table.
Cylinder formulas
| Quantity | Formula | Example: r = 15 cm, h = 50 cm |
|---|---|---|
| Volume | V = πr²h | 35,342.92 cm³ = 35.34 L |
| Volume from diameter | V = πd²h ÷ 4 | π × 30² × 50 ÷ 4 = 35,342.92 cm³ |
| Base area | A = πr² | 706.86 cm² |
| Lateral area | 2πrh | 4,712.39 cm² |
| Total surface area | 2πr(r + h) | 6,126.11 cm² |
Volume unit conversions
| From | Equals |
|---|---|
| 1 cm³ | 1 mL = 0.001 L |
| 1 m³ | 1,000 L = 264.172 US gal |
| 1 in³ | 16.387 mL |
| 1 ft³ | 28.317 L = 7.4805 US gal |
| 1 yd³ | 764.555 L = 27 ft³ |
| 1 US gallon | 3.785412 L = 231 in³ |
| 1 imperial gallon | 4.54609 L |
Frequently asked questions
What is the formula for the volume of a cylinder?
V = πr²h, where r is the radius of the circular base and h is the height. It is the area of the base (πr²) times the height. If you know the diameter d, use V = π(d/2)²h = πd²h/4.
How do I convert cylinder volume to liters?
Work out the volume in cubic centimeters and divide by 1,000 (1 L = 1,000 cm³), or in cubic meters and multiply by 1,000. For a 30 cm diameter, 50 cm tall cylinder: π × 15² × 50 ≈ 35,343 cm³ ≈ 35.34 L.
How many gallons are in a cylinder?
Compute the volume in cubic inches and divide by 231 (1 US gallon = 231 in³), or in cubic feet and multiply by about 7.4805. A cylinder 2 ft across and 3 ft tall holds π × 1² × 3 ≈ 9.42 ft³ ≈ 70.5 US gallons.
What is the surface area of a cylinder?
The curved (lateral) surface is 2πrh. Adding the two circular ends gives the total surface area 2πrh + 2πr² = 2πr(h + r). Use the lateral area for labels or wraps, and the total area for painting a closed can.
Does it matter if the cylinder is lying on its side?
Not for the total volume: use the length as the height. The fill-level option assumes an upright cylinder, where volume is proportional to the liquid depth. For a horizontal tank the relationship is not linear, so a partly full horizontal tank needs a different formula.
How do I measure the radius of a pipe or tank?
Measure the diameter across the widest point and halve it, or measure the circumference with a tape and divide by 2π (about 6.283). For a pipe's capacity, use the inside diameter, not the outside.