Topic hub

Solve a dimension calculator

Work backwards: enter the volume you need plus one dimension, and solve for the missing height, radius or diameter.

Sometimes you know the volume you need and have to find a dimension to match — the height of a tank to hold so many litres, say. This solve a dimension calculator rearranges V = π r² h for you and solves for the height, radius or diameter.

How the calculation works

  1. Choose which dimension you need — height, radius or diameter.
  2. Enter the target volume you want the cylinder to hold.
  3. Enter the one dimension you already know.
  4. The tool rearranges V = π r² h and solves for the rest.

Worked example. Take a cylinder with a diameter of 10 cm (so a radius of 5 cm) and a height of 25 cm. The base area is π × 5² = 78.54 cm², and multiplying by the height gives a volume of about 1.96 litres (1,963 cm³ · 0.52 US gallons).

For anything that holds liquid, measure the inside of the cylinder — the wall takes up space that the contents cannot.

Every solve a dimension page

Each page below targets a specific question and opens with the calculator ready to go:

Good to know

How do I find the height of a cylinder from its volume?
Rearrange the formula: h = V ÷ (π r²). Enter the target volume and the radius above, and the height is solved for you.
How do I find the radius from volume and height?
Use r = √(V ÷ (π h)). The tool can also return the diameter, which is simply twice the radius.

Related tools