Cylinder Volume Calculator
A cylinder is a stack of identical circles: circle area πr² times the height. Tanks, pipes, cans and round columns use this formula.
V = πr²h
- Surface area
- 207.345 ft²
- Base area = π × 3² = 28.2743 ft²
- V = base × h = 28.2743 × 8 = 226.195 ft³
Volume in other units
| m³ | 6.4051 |
| liters | 6,405.12 |
| ft³ | 226.195 |
| yd³ | 8.3776 |
| in³ | 390,864 |
| US gallons | 1,692.05 |
| cm³ (mL) | 6,405,120 |
How to find the volume of a cylinder
Volume: V = πr²h. Surface area: SA = 2πr(r + h).
- Measure in one unit. The answer comes out in that unit cubed (ft³, m³).
- Substitute into the formula; the calculator shows the steps with your numbers.
- Read liters, gallons, cubic yards and more in the conversion table. 1 ft³ ≈ 7.48 US gallons ≈ 28.32 liters.
Three cones fill one cylinder
Take a cone and a cylinder with the same round base and the same height. Pour the cone full of water into the cylinder three times and it's full — which is why the cone formula is ⅓ πr²h. The same ⅓ links a pyramid to the box around it.
Cylinder is ⅓ full
Questions people ask
How many gallons does a cylinder tank hold?
Work out the volume in cubic feet and multiply by 7.48 (US gallons per ft³). Use feet as the unit here and read the gallons row.
Radius or diameter?
The formula uses the radius — half the diameter. Measuring a 24 in wide tank? r = 12 in.
Stuck on a word problem?
Paste a homework question or describe your project. The AI tutor names the formula and works it through step by step. Always check the result with the calculator above.