Tank Volume Calculator
Tank Volume Calculator works out Volume of material and Internal capacity from Measurement supplied, Outer radius or diameter and Height / length. The default figures on this page give internal capacity of 15.707963; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
5 steps
- Outer radius R = 1 ft, height/length h = 5 ft
- Volume V = pi r^2 h = pi x 1 x 5 = 15.707963 ft^3
- Curved surface = 2 pi R h = 31.415927 ft^2
- Total surface = curved + 2 x end face = 31.415927 + 2 x 3.1415927 = 37.699112 ft^2
- Capacity in US gallons = 117.50373; in litres = 444.79999.
Its 6 worked examples are re-run on every release, last on 15 September 2026. What changed
What the Tank Volume Calculator calculates
Computes volume, surface area, capacity, weight and partial-fill volume for solid or hollow cylinders and cylindrical tanks.
How to use this Tank Volume Calculator
Enter Measurement supplied, Outer radius or diameter, Height / length and Orientation. Volume of material updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Volume of material, Internal capacity and Lateral (curved) surface area.
The method follows Weisstein, Eric W. "Cylinder." MathWorld — A Wolfram Web Resource, Weisstein, Eric W. "Circular Segment." MathWorld (horizontal tank partial-fill area) and NIST Special Publication 811 (unit factors used for capacity and mass output).
What you can compare
Change one input at a time to see how it affects Volume of material, Internal capacity and Lateral (curved) surface area. The inputs you can vary are Measurement supplied, Outer radius or diameter, Height / length, Orientation, Fill depth (optional) and Length unit.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
How to calculate tank volume?
Computes volume, surface area, capacity, weight and partial-fill volume for solid or hollow cylinders and cylindrical tanks. Open “How this is worked out” beside the result to see each step for your own figures.
How many gallons is my tank calculator?
It needs Measurement supplied, Outer radius or diameter, Height / length, Orientation, Fill depth (optional) and Length unit. Nothing else is required, and the figures stay in your browser.
How to calculate aquarium tank volume?
The result gives Volume of material, Internal capacity, Lateral (curved) surface area, End-face area, Total surface area and Outer radius, each labelled with its unit so the figure can be read on its own.
How to figure tank volume in gallons?
The page opens with worked default figures: internal capacity of 15.707963. Replace them with your own and every figure updates as you type.
What information do I need for the Tank Volume Calculator?
You need Measurement supplied, Outer radius or diameter, Height / length, Orientation, Fill depth (optional), Length unit, Density (optional) and Density unit. The page opens with default figures that give internal capacity of 15.707963, so you can see the scale before entering your own.
What does this Tank Volume Calculator show?
It shows Volume of material, Internal capacity, Lateral (curved) surface area, End-face area, Total surface area, Outer radius, Inner radius and Outer circumference, with the working and any warnings for your entries.