Pool Volume Calculator – Gallons, Liters & Chemical Dosing
Calculate your swimming pool volume in gallons and liters for any pool shape.
Swimming Pool Volume and Chemical Dosing
Knowing your pool's exact volume is essential for correct chemical treatment. Under-dosing leaves bacteria and algae untreated; over-dosing wastes chemicals and can irritate swimmers' skin and eyes.
| Pool Type | Typical Volume | Gallons |
|---|---|---|
| Small above-ground (12×24 ft, 4 ft deep) | ~10,800 gal | 10,800 |
| Standard residential (16×32 ft, 5 ft avg) | ~19,200 gal | 19,200 |
| Large residential (20×40 ft, 5.5 ft avg) | ~33,000 gal | 33,000 |
| Olympic pool (50m × 25m × 2m) | 2,500 m³ | 660,430 |
Formulas: Rectangular pool: L × W × Average Depth × 7.48 gallons/cu ft. Circular pool: π × r² × depth × 7.48. For irregular shapes, break into rectangles and sum. Proper water chemistry requires testing pH (target 7.2–7.6), free chlorine (1–3 ppm), alkalinity (80–120 ppm), and calcium hardness (200–400 ppm) at least weekly.
How many gallons is my pool?
Rectangular pool in gallons: length (ft) × width (ft) × average depth (ft) × 7.48. For a 16×32 ft pool at 5 ft average depth: 16 × 32 × 5 × 7.48 = 19,148 gallons.
How much chlorine do I add per gallon?
To raise chlorine by 1 ppm: add approximately 0.013 oz of granular chlorine (65% dichlor) per 1,000 gallons. A 20,000-gallon pool needs about 8 oz to raise chlorine by 3 ppm.