Tank Volume Calculator
Find the capacity of a tank in gallons and liters, and how much is in it at a fill depth, for cylindrical, oval, capsule, rectangular and spherical tanks.
Change the values and press Calculate to work out your own figures.
Choose the shape, enter its sizes and (optionally) the fill depth.
Show the working
- capacity = the shape's volume; US gallon = 231 cubic inches
How to use it
Choose the shape, enter its sizes and (optionally) the fill depth.
Lengths can be decimals, fractions or tape entries such as 12' 6 1/2" (in feet or inches). Prices are optional.
Key facts
cylinder = π r² L; sphere = 4/3 π r³; capsule = π r² L + 4/3 π r³ partly filled horizontal cylinder: L × (r² acos((r − d)/r) − (r − d)√(2rd − d²))
Oval tanks
An oval tank here has a flat-sided cross-section with round ends (a stadium shape), the usual shape for fuel-oil tanks.
Gallons
A US gallon is exactly 231 cubic inches (3.785411784 L).
Questions
How many gallons in a 36 × 72 in cylinder?
317.26 US gallons.
How much is in it half full?
Half: 158.63 gallons.
Formulas
cylinder = π r² L; sphere = 4/3 π r³; capsule = π r² L + 4/3 π r³ partly filled horizontal cylinder: L × (r² acos((r − d)/r) − (r − d)√(2rd − d²))
Sources
Limitations
- Material densities are typical values (the midpoint of the commonly published range); real loads vary with moisture, grading and compaction, so check with your supplier or type in their density.
- Tank results are the geometric volume; real tanks have wall thickness and fittings.