Spherical Tank
Spherical Tank Volume Calculator
Calculate liquid volume in a spherical tank from the diameter and the dipstick reading.
Tank dimensions
Tank diagram
Liquid is below the dipstick level, at the very bottom of the sphere.
Calculated volume
- Tank capacity
- Liquid depth
- Remaining capacity
| Dip | Volume (gal) | Volume (L) | % Full |
|---|
About this calculator
How spherical tank volume is calculated
The liquid in a sphere forms a spherical cap. A cap of depth h in a sphere of radius r has the volume:
V = (π·h²/3)·(3r − h)
This is algebraically equivalent to the cap formula used by the calculator, V = (−π/3)(D − 2r)(D + r)² with D = h − r. Cubic inches become US gallons by dividing by 231.
Note: the total tank capacity is 4πr³/3. The residual (empty) volume is the capacity minus the liquid volume.
Assumptions
Measurement guide
The tank is a true sphere. The dipstick reads from the lowest point, so a dip of one diameter means the tank is full. Measure the diameter at the widest ring.