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Oblique cylinder calculator
A leaning cylinder has the same volume as an upright one — as long as you use the perpendicular height, not the slant.
This oblique cylinder calculator handles slanted cylinders the right way. The one rule to remember is to measure the perpendicular height — straight up from base to top — not the longer slanted edge.
How to work it out
- Measure across the circular end — the diameter or radius.
- If you measured the diameter, halve it to get the radius r.
- Square the radius and multiply by π to get the base area.
- Multiply the base area by the height h: V = π r² h.
- Convert the result into your preferred unit above.
Worked example. Take a cylinder with a diameter of 20 cm (so a radius of 10 cm) and a height of 40 cm. The base area is π × 10² = 314.16 cm², and multiplying by the height gives a volume of about 12.57 litres (12,566 cm³ · 3.32 US gallons).
Measure the perpendicular height — straight up between the two ends — not the longer slanted side, or the volume will come out too high.
Every oblique cylinder page
Each page below targets a specific question and opens with the calculator ready to go:
Questions people ask
How do you find the volume of an oblique cylinder?
V = π r² h with the perpendicular height. By Cavalieri's principle, a slanted cylinder has the same volume as an upright one with the same base and height.