Tank Volume Calculator
Capacity and partial-fill volume for rectangular, cylindrical and spherical tanks.
What is Tank Volume?
A tank's capacity is one formula; how much is in it at a given depth is a different one for each shape, and the difference is not academic. A vertical cylinder fills linearly (area × depth), a rectangular tank likewise, but a horizontal cylindrical tank fills as a circular *segment* — the middle holds far more per centimetre of depth than the ends — and a sphere fills as a spherical cap, which is non-linear at both ends. A dipstick reading converted linearly in a horizontal tank can be wrong by a factor of two around the quarter marks.
How it works
Capacity comes from the shape's own formula: length × width × height, π·r²·h for a cylinder, 4⁄3·π·r³ for a sphere. Fill volume is then computed from the depth the fill level implies, using area × depth for the vertical and rectangular cases, the circular segment formula L × [r²·acos((r−h) ÷ r) − (r−h)·√(2rh − h²)] for a horizontal cylinder, and the spherical cap π·h²·(3r − h) ÷ 3 for a sphere. The page names the fill formula it used so the curve being applied is visible.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.