These are approximate volumes at average depths. Use the pool volume calculator for precise results based on your specific dimensions.
Rectangular Pool Volumes (at 4.5 ft average depth)
| Length (ft) | Width (ft) | Approx. Volume (gal) |
|---|
| 12 | 24 | 9,700 |
| 16 | 32 | 17,200 |
| 18 | 36 | 21,800 |
| 20 | 40 | 26,900 |
| 25 | 50 | 42,000 |
Round / Circular Pool Volumes (at 4.5 ft depth)
| Diameter (ft) | Approx. Volume (gal) |
|---|
| 12 | 3,800 |
| 15 | 5,950 |
| 18 | 8,600 |
| 21 | 11,700 |
| 24 | 15,300 |
| 27 | 19,400 |
| 30 | 23,900 |
Hot Tub / Spa Volumes
| Size | Person Capacity | Approx. Volume (gal) |
|---|
| Small | 2–3 | 175–250 |
| Medium | 4–5 | 250–400 |
| Large | 6–7 | 400–500 |
| Extra Large | 8+ | 500–600+ |
Notes
- Use the pool volume calculator for exact dimensions.
- Average depth = (shallow end + deep end) / 2 for pools with a gradual slope.
Sources:- Pool & Hot Tub Alliance — Pool & Spa Operator Handbook, 2022
Last reviewed: 2026-06-01
