About the Capsule Calculator
A capsule is a cylinder with a half sphere on each end, like a medicine capsule or a fuel tank with rounded ends. This calculator takes the radius and the length of the straight middle part and gives the volume, the surface area and the total length from tip to tip. Type the radius of the ends and the length of the straight part and the capsule volume appears at once, with a few related figures underneath, and you can copy the result with one tap. The sums run in your browser, so nothing you enter is uploaded.
Updated October 2026
How to use the Capsule Calculator
- 1Enter the radius of the ends and the length of the straight part.
- 2Pick the units or options from the menus if the capsule volume tool offers them.
- 3Read the capsule volume in the large result box.
- 4Look at the extra rows for related figures.
- 5Press Copy result to keep the answer.
When you need the capsule volume
Pharmacists and manufacturers use the shape for pills and tablets, tank designers for rounded storage vessels, and product designers for cases and bottles. The volume tells how much the capsule holds, and the surface area how much material or coating it needs.
Splitting the capsule into one cylinder and one sphere makes the formula easy to check: the two half spheres at the ends are together one full sphere of the same radius.
How the capsule volume is worked out
Volume = π × r² × h + 4⁄3 × π × r³. Surface area = 2π × r × h + 4π × r². Total length = h + 2r. A capsule with a radius of 2 and a straight part of 6 has a volume of 75.40 + 33.51 = 108.91, a surface area of 75.40 + 50.27 = 125.66 and a length of 10. With a straight part of 0 it is a plain sphere.
Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.
- Volume, surface area and length
- Zero straight part allowed
- Works in any unit
Mistakes to avoid with capsule volume
The length of the straight part does not include the rounded ends. If you measure the whole length from tip to tip, subtract two radii to get the straight part. Mixing the two is the most common mistake.
On phone and computer
On a phone, type into the boxes one after another and read the capsule volume underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the capsule volume move. The capsule calculator works the same on both. A capsule is a cylinder with two half-spheres, so test each part with Cylinder Calculator and Sphere Calculator. Volume Calculator and Surface Area Calculator handle other solids with the same ideas.
Features
- Straight part excludes the ends
- Ends make one full sphere
- Volume units are cubed
- Clear messages when the capsule volume inputs make no sense
- Copy the result with one tap
- Private: nothing is uploaded
Frequently asked questions
How do I calculate capsule volume?
Volume = π × r² × h + 4⁄3 × π × r³. Surface area = 2π × r × h + 4π × r². Total length = h + 2r. A capsule with a radius of 2 and a straight part of 6 has a volume of 75.40 + 33.51 = 108.91, a surface area of 75.40 + 50.27 = 125.66 and a length of 10. With a straight part of 0 it is a plain sphere.
What is the formula for capsule volume?
Volume = π × r² × h + 4⁄3 × π × r³. Surface area = 2π × r × h + 4π × r². Total length = h + 2r. The capsule calculator applies it exactly and rounds only the displayed answer to six significant figures.
How do I find the straight length from the total?
Subtract twice the radius from the total length.
What is the volume in litres?
If the lengths are in centimetres, divide the volume in cubic centimetres by 1,000 to get litres.
Is this the same as a cylinder?
A cylinder has flat ends. A capsule has hemispherical ends, which adds a sphere's volume.
Is this capsule calculator free and private?
Yes. It is free, needs no account and runs in your browser, so the numbers you type are not uploaded or stored.