Pool Volume Calculator
Calculate swimming pool volume in gallons and litres for rectangular, round, oval and kidney pools, plus fill time, pump turnover and chemical dose scaling.
Filling, turnover and dosing
Volume = surface area × average depth, where average depth = (shallow + deep) ÷ 2. Round pools use πr², ovals use π ÷ 4 × length × width, and kidney or freeform shapes take 85% of the widest length × width rectangle. Cubic feet convert at exactly 7.4805 US gallons. A sloping floor that is not a simple ramp — a hopper bottom, a wide beach entry or a spa ledge — will shift the real figure by a few per cent, so treat this as a close estimate and always add chemicals gradually while testing.
What is the Pool Volume Calculator?
The ByteTools Pool Volume Calculator works out how much water your pool holds. Choose rectangular, round, oval or kidney, enter the dimensions and the shallow and deep end depths, and it averages the depth and returns the volume in US gallons, litres, cubic metres and cubic feet, along with the surface area and the weight of the water.
- Rectangular, round, oval and kidney or freeform shapes
- Average depth from separate shallow and deep end measurements
- Volume in US gallons, litres, cubic metres and cubic feet at once
- Fill time from a hose flow rate and turnover time from your pump
- Chemical dose scaled from any 'per 10,000 gallons or litres' label rate
- Water weight in pounds and kilograms; everything computed in-browser
How to use the Pool Volume Calculator
- 1
Pick imperial or metric units and the shape that best matches your pool.
- 2
Enter the length and width (or the diameter for a round pool).
- 3
Enter the shallow-end and deep-end depths — use the same figure twice for a constant-depth pool.
- 4
Read the volume in gallons, litres, cubic metres and cubic feet, with the surface area and water weight.
- 5
Add your hose and pump flow rates and a label dose per 10,000 to get fill time, turnover time and the dose for your pool.
About the Pool Volume Calculator
The ByteTools Pool Volume Calculator works out how much water your pool holds. Choose rectangular, round, oval or kidney, enter the dimensions and the shallow and deep end depths, and it averages the depth and returns the volume in US gallons, litres, cubic metres and cubic feet, along with the surface area and the weight of the water.
Volume is only useful once you can act on it, so three practical numbers follow. Fill time comes from your hose flow rate, turnover time from your pump's flow rate, and the chemical panel scales any label dose written 'per 10,000 gallons' to your actual pool — the single calculation every pool owner does again and again.
It all runs locally in your browser with nothing uploaded. Treat the answer as a close estimate: hopper bottoms, beach entries and spa ledges shift the real figure by a few per cent, so always add chemicals gradually and test the water rather than trusting arithmetic alone.
Frequently asked questions
How many gallons is a 16x32 pool?
A 16 by 32 foot rectangular pool with an average depth of 5.5 feet holds about 21,000 US gallons, or roughly 80,000 litres. Change the shallow and deep end depths above to match your own pool for an exact figure.
How do I calculate my pool volume?
Multiply the surface area by the average depth, then convert cubic feet to gallons at 7.4805 gallons per cubic foot. Average depth is simply (shallow end + deep end) ÷ 2 for a pool with a straight slope, which is what this calculator uses.
How do you work out the volume of a kidney-shaped pool?
The usual approach is to take the widest length and width as if it were a rectangle and discount it by about 15 per cent to allow for the curves. That is the 0.85 factor applied here. For an unusual freeform shape, measuring in sections and adding them is more accurate.
How long does it take to fill a swimming pool?
Divide the volume by your hose flow rate. A typical garden hose delivers around 9 gallons per minute, so a 21,000 gallon pool takes roughly 39 hours from one hose. A water delivery truck is often quicker and, in drought areas, sometimes the only option.
What is pool turnover time?
It is how long the pump takes to move a volume of water equal to the whole pool through the filter. Most residential pools aim for one turnover in 8 to 10 hours. Enter your pump's flow rate at your system head — not its badge rating — for a realistic figure.
How do I scale a chemical dose to my pool size?
Almost every product label gives a dose per 10,000 gallons or per 10,000 litres. Divide your pool volume by 10,000 and multiply the label dose by that factor — the calculator shows both the factor and the resulting amount. Always add gradually and retest.
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