Capsule volume calculator
Useful for tanks with rounded ends and pill shapes. Enter the radius and the overall end-to-end length.
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How to use it
- Enter radius, total length and length unit.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Cylinder part a = total length − 2r, volume = πr² × (4/3 r + a), surface area = 2πr(2r + a).
Example
Inputs: Radius = 2, Total length = 9, Length unit = Centimeter (cm). Result: Volume: 96.3422 cm³; Surface area: 113.0973 cm²; Cylinder section length: 5 cm.
Limits and caveats
- Assumes true hemispherical ends; tanks with elliptical or dished heads need a different formula.
- Results are in the cube or square of the unit you chose, so enter every dimension in that same unit.
Questions about this tool
What is the capsule volume formula?
The middle cylinder πr²a plus one full sphere 4/3 πr³ formed by the two ends.
Do I enter the total length or the cylinder length?
Enter the overall end-to-end length; the calculator subtracts the diameter to get the cylinder part.
What if the length equals the diameter?
The cylinder part vanishes and the capsule becomes a full sphere.