Compute cylinder volume from diameter or radius and height in multiple units.
Presets
Volume in other units
Surface area & water weight
Details
Formula derivation
A right circular cylinder has two parallel circular bases connected by a straight side. Its volume equals the area of the base circle multiplied by its height:
V = A_base × h = π × r² × h
If you only know the diameter d, substitute r = d / 2:
V = π × (d / 2)² × h = (π × d² × h) / 4
Lateral (side) surface area is the circumference of the base times the height: A_lateral = 2 × π × r × h. Total surface area adds the two circular caps: A_total = 2 × π × r × h + 2 × π × r².
π precision used
This calculator uses JavaScript's Math.PI, which stores π to 15–17 significant decimal digits (3.141592653589793). That is more than adequate for any engineering, construction, or manufacturing task — tank fabrication tolerances typically reach only 4–6 significant figures. Rounding to a shorter π such as 3.14 or 22/7 can introduce errors of 0.05 % or more on large volumes.
Quick reference (water-filled cylinders)
| Diameter × Height | Volume (L) | Water weight (kg) |
|---|---|---|
| 10 cm × 20 cm | 1.57 L | 1.57 kg |
| 30 cm × 50 cm | 35.34 L | 35.34 kg |
| 50 cm × 100 cm | 196.35 L | 196.35 kg |
| 1 m × 1 m | 785.40 L | 785.40 kg |
| 1 m × 2 m | 1,570.80 L | 1,570.80 kg |
| 2 m × 3 m | 9,424.78 L | 9,424.78 kg |
FAQ
How do I find the radius if I only have the diameter?
The radius is always half the diameter: r = d / 2. For a pipe with a 30 cm outer diameter, the outer radius is 15 cm. Measure the diameter across the widest point of the circle, passing through the centre — then divide by 2. This calculator also accepts the diameter directly in the first tab, so you don't have to do the division yourself.
How do I convert between volume units?
Use these exact conversions: 1 m³ = 1,000 L = 1,000,000 mL = 35.3147 ft³ = 61,023.7 in³ = 264.172 US gallons. For quick estimates: 1 litre ≈ 0.264 US gallon, 1 ft³ ≈ 28.32 L, 1 US gallon ≈ 3.785 L. The calculator above shows all six volume units at once so you don't need a separate conversion step.
Why does volume in cubic feet matter for shipping?
Freight carriers (LTL, ocean, and air) charge by dimensional weight, which is computed from cubic feet or cubic metres. A cylinder that looks small can take up a surprising amount of pallet space once you account for the bounding box around it. Knowing the exact ft³ helps you book the right pallet size, estimate container fill rate, and avoid surcharges for under-declared volume.
How accurate is the water-weight output?
Fresh water at 4 °C has a density of exactly 1 kg per litre, so volume in litres equals mass in kilograms. At room temperature (20 °C) water density drops to about 0.998 kg/L — a 0.2 % difference, negligible for most applications. Salt water (≈1.025 kg/L) and other liquids have different densities, so multiply the litre value by the actual density for non-water fluids.
Can I use this calculator for pipes, tanks, or silos?
Yes — any right circular cylinder works: water tanks, fuel drums, concrete columns, grain silos, pipes, posts, rollers. For hollow pipes, calculate the outer-diameter volume, then subtract the inner-diameter volume to get the wall-material volume. For partially filled horizontal cylinders, use a horizontal cylinder tank calculator instead, because the formula becomes a circular-segment integral rather than the simple πr²h.
Compute the internal volume of any right circular cylinder from its diameter (or radius) and height, with independent unit selectors on every dimension: metres, centimetres, millimetres, inches, or feet. Results appear simultaneously in cubic metres, litres, millilitres, US gallons, cubic feet, and cubic inches, with copy-to-clipboard on every value. Lateral surface area, total surface area (including both caps), and water weight at 1 kg per litre are shown alongside the volume. Example: a 1 m diameter by 2 m height water tank holds 1.5708 m³ = 1,570.8 L = 415 US gallons = 55.45 ft³, with a lateral area of 6.28 m² and water weight of 1.57 tonnes. Presets cover a beverage can, a 55-gallon drum, and a 1 m by 2 m water tank. Formula V = pi r squared h and derivation are shown in an expandable details block.