How to Calculate Pool Volume
Select your pool shape, enter the dimensions in feet, and the calculator determines the volume in gallons, liters, and cubic feet. If your pool has a shallow and deep end, enter both depths for an accurate average.
Pool Volume Formulas
Rectangular Pool
Volume = Length × Width × Average Depth
The most common pool shape. Multiply all three dimensions to get cubic feet, then multiply by 7.48 for gallons.
Circular Pool
Volume = π × (Diameter ÷ 2)² × Average Depth
Common for above-ground pools. Measure the diameter across the widest point.
Oval Pool
Volume = π × (Length ÷ 2) × (Width ÷ 2) × Average Depth
Uses the ellipse area formula. Measure the longest and widest dimensions.
Oblong Pool (Stadium Shape)
Volume = (Rectangle area + Circle area) × Average Depth
A rectangle with semicircular ends. The calculator computes the rectangular center section plus the two semicircles that form a full circle.
Average Depth
Most pools slope from shallow to deep. The average depth is simply:
Average Depth = (Shallow Depth + Deep Depth) ÷ 2
For flat-bottom pools, just enter the single depth value.
Unit Conversions
- 1 cubic foot = 7.48052 US gallons
- 1 cubic foot = 28.3168 liters
- 1 US gallon = 3.78541 liters
Why Pool Volume Matters
- Chemical dosing: Chlorine, pH, alkalinity, and stabilizer amounts are based on water volume
- Equipment sizing: Pumps and filters are rated for specific pool volumes
- Fill time: A garden hose at ~9 GPM fills about 540 gallons per hour
- Water cost: Multiply volume by your local water rate per gallon
- Heater sizing: BTU requirements depend on water volume and desired temperature rise
Common Pool Sizes
- 12 ft round above-ground: ~3,400 gallons (4 ft depth)
- 15 ft round above-ground: ~5,300 gallons (4 ft depth)
- 24 ft round above-ground: ~13,500 gallons (4 ft depth)
- 12 × 24 ft in-ground: ~8,600 gallons (3–6 ft depth)
- 16 × 32 ft in-ground: ~19,200 gallons (3.5–8 ft depth)
- 20 × 40 ft in-ground: ~30,000 gallons (3.5–8 ft depth)