Pool Data Sheet
Work the volume out once, write it here, and tape it inside the equipment cupboard. Every dose you ever measure depends on this number.
BFCBrilliance · bfcbrilliance.com/tools/pool-volume-calculator
The pool
- Shape
- Length
- Width
- Shallow end
- Deep end
- Average depth
- GALLONS
- Surface area
- Date measured
If your pool has sections, do each separately and add
| Section | Length | Width | Avg depth | Cubic feet | Gallons |
|---|---|---|---|---|---|
The arithmetic
- Rectangle area
- length x width
- Round or oval area
- length x width x 0.7854 (pi/4)
- Round pool
- diameter in BOTH length and width
- Average depth
- (shallow + deep) / 2, for an even slope
- Volume
- area x average depth = cubic feet
- US gallons
- cubic feet x 7.480519 (exact: 1728 / 231)
- Litres
- gallons x 3.785412
- ⚠ Measure
- the WATER depth, not the wall height
Measuring it properly, once
- Depth measured to the WATERLINE, not the top of the wall
- Round pool - diameter entered in both boxes
- Flat shallow area plus a separate deep well? Do them as sections
- Steps and benches ignored - they are a small over-estimate, and safe
- Measurements taken twice, by two people if possible
- Volume written somewhere permanent, not on a scrap of paper
- Surface area noted too - covers are sized by it
An error here repeats forever
Every chemical instruction is per volume. Get this number wrong and you are wrong by the same proportion in the same direction on every dose, for as long as you own the pool - and because the error is consistent it never announces itself as a mistake. It is the one measurement worth doing carefully and only once.
The average-depth shortcut has one failure case
Averaging the shallow and deep ends is exact when the floor slopes evenly between them. It reads HIGH for the common older layout of a flat shallow section, a sudden drop, then a flat deep well — that shape holds less water than the slope it is being modelled as. Measure those pools in sections.