Pool Ratio

15 ft round pool, 42 in deep: how many gallons?

A 15 ft round pool, 42 in deep with 3.5 ft of water holds about 4,630 US gallons (17,514 litres). Here is what that means for salt and chemicals.

Last updated · Checked against published product doses · How we calculate

Volume
4,630 gal
17,514 litres · 3.5 ft of water
Salt to 3,200 ppm (new salt pool)124 lb · 4 × 40 lb bags
10% liquid chlorine per +1 ppm6 fl oz
Stabilizer 0 → 40 ppm1.5 lb
Baking soda per +10 ppm alkalinity0.6 lb
Calcium chloride (77%) per +10 ppm9 oz

Open the chemical calculator for this pool →

The maths

  1. Area = π × 7.5² = 176.7 sq ft
  2. Volume = 176.7 × 3.5 = 619 cu ft
  3. 619 cu ft × 7.48 gal per cu ft

= 4,630 US gallons

Real pools vary: water levels sit a few inches below the wall top, floors slope and corners are rounded. If your pool’s depth differs, adjust it in the volume calculator.

Frequently asked questions

How many gallons is a 15 ft round pool, 42 in deep?

About 4,630 US gallons (17,514 litres) with 3.5 ft of water.

How much salt does a 15 ft round pool, 42 in deep need?

About 124 lb (56 kg) to bring fresh water to 3,200 ppm, or 4 bags of 40 lb. Check your salt cell’s target first.

How much chlorine does a 15 ft round pool, 42 in deep need?

Each +1 ppm of free chlorine takes about 6 fl oz of 10% liquid chlorine. With stabilizer at 40 ppm, keep free chlorine around 4.6 ppm.

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