About this calculator
Water capacity of a pool, pond or hot tub, for chemical dosing, heater and pump sizing, and fill costs.
How it’s calculated
Volume = surface area × average depth. Average depth = (shallow + deep) ÷ 2. 1 cu ft = 7.48 US gallons.
Worked example
With these inputs:
- Shape
- Rectangle
- Length / diameter
- 32 ft
- Width
- 16 ft
- Shallow end depth
- 3.5 ft
- Deep end depth
- 6 ft
the result is:
- Water volume
- 18,192.62 gal
- Surface area
- 512 sq ft
- Average depth
- 4' 9"
- Cubic metres
- 68.9 m³
Tips from the trade
- Follow chemical labels against this volume. Never guess a dose.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and local building codes before ordering.