Pool Volume Calculator
Select your pool shape, enter dimensions in feet, and get your pool volume in US gallons. Formulas verified against Pentair and SwimUniversity standards (June 2026).
Pool Dimensions
Same as shallow end if flat-bottom pool.
Volume Formulas by Shape
| Shape | Formula | Factor |
|---|---|---|
| Rectangle | L × W × Avg Depth × 7.48 | 1.000 |
| Round | π × (D/2)² × Avg Depth × 7.48 | 0.785 |
| Oval | L × W × 0.785 × Avg Depth × 7.48 | 0.785 |
| Kidney | L × W × 0.585 × Avg Depth × 7.48 | 0.585 |
7.48 = US gallons per cubic foot. Kidney factor 0.585 is the industry-standard approximation. Source: Pentair pool volume calculator; SwimUniversity — verified June 2026.
Use your volume in: Salt Calculator · Shock Calculator · Chlorine Calculator · Alkalinity Calculator · Stabilizer Calculator
Frequently Asked Questions
Every pool chemical dose is calculated per 10,000 gallons of water. An inaccurate volume estimate leads to under- or over-dosing — both of which waste money and can harm swimmers or equipment.
The kidney shape uses a 0.585 factor (compared to a rectangle of the same outer dimensions). This is the industry-standard approximation established by pool professionals. For an exact volume, measure by filling from a known water source and watching your meter.
Use the average depth: add the shallow-end depth plus the deep-end depth, then divide by 2. For example, a pool that is 3 ft at the shallow end and 8 ft at the deep end has an average depth of (3+8)/2 = 5.5 ft.
The physical volume stays the same, but effective water volume decreases through evaporation, splash-out, and backwashing. Always top up to the normal water line before calculating chemical doses.
Rectangular and round formulas are very accurate. Oval and kidney formulas are geometric approximations — typically within 5–10% of actual volume. For precise chemical dosing, consider a professional measurement or use a calibrated flow meter when filling.