Water & Wastewater
Tank and Basin Volume
Volume of a cylindrical or rectangular tank at a given level, in gallons, cubic feet, and cubic metres, with the volume per foot of depth.
Calculated reference results
- Volume at this level
- 63,452gal
- Volume at this level
- 8,482.3cu ft
- Volume at this level
- 240.19cu m
- Full capacity
- 126,904gal
- Percent full
- 50.0%
- Volume per foot of depth
- 5,288gal per ft
- Volume per inch of depth
- 440.6gal per in
- Plan area
- 706.86sq ft
At 24.00 ft
Useful for turning a level change into a volume for a drawdown test.
The arithmetic
- Area = pi x (15.00 ft) squared = 706.86 sq ft
- Volume = 706.86 sq ft x 12.00 ft = 8,482.3 cu ft
- Gallons = 8,482.3 x 7.48052 = 63,452 gal
What this does not account for
- Assumes vertical walls and a flat bottom. Coned, dished, or benched bottoms hold less than this near the floor, which matters most at the low levels a pump-off setpoint uses.
- A drawdown test using the volume per foot figure is one of the few practical ways to verify a pump rate in the field, and it is worth doing at commissioning.
How this is calculated
A cylindrical tank holds pi multiplied by the radius squared, multiplied by the liquid depth. A rectangular basin holds length multiplied by width multiplied by depth. Multiply cubic feet by 7.48 to get US gallons.
Formulas
Cylindrical volume = pi x radius squared x depth
Rectangular volume = length x width x depth
Gallons = cubic feet x 7.48052
Assumptions and limitations built into this calculator
- Vertical walls, flat bottom, uniform cross-section.
Frequently asked questions
- How do I verify a pump rate in the field?
- Isolate the inflow if you can, run the pump, and time a known level change. Volume per foot multiplied by the level change, divided by the run time, gives the actual pumping rate.
Direct contact
Have a controls question?
Reach Eric Sullivan directly about anything on this site, a controls or automation topic, or one of his personal projects.