What Size Swimming Pool Heater Do I Need? Above Ground Pools | |||
| Pool Dimension (feet) | Volume When Filled to 6'' Below Top Rim | Minimum Recommended Heater Size | |
| Round Pools - Diameter | UK Gallons / (Litres) | kW - Kilo Watts | |
| 12' x 3' | 1761-gal / (7994-ltr) | 4.5-kW | |
| 15' x 3' | 2752-gal / (12494-ltr) | 6-kW | |
| 15' x 4' | 3854-gal / (17492-ltr) | 9-kW | |
| 18' x 4' | 5548-gal / (25187-ltr) | 9-kW | |
| Oval Pools L x W x D | UK Gallons / (Litres) | kW - Kilo Watts | |
| 16' x 10' x 3' | 2157-gal / (9792-ltr) | 4.5-kW | |
| 24' x 12' x 4' | 5605-gal / (25446-ltr) | 9-kW | |
| 30' x 15' x 4' | 9592-gal / (43547-ltr) | 15-kW | |
In Ground Pools | |||
| Pool Dimension (feet) | Volume When Filled to 6'' Below Top Rim |
| |
| Dimension L x W x D | UK Gallons / (Litres) | kW - Kilo Watts | |
| 20' x 10' x 4.5' | 4983-gal / (22620-ltr) | 9-kW | |
| 24' x 12' x 4.5' | 7175-gal / (32573-ltr) | 12-kW | |
| 30' x 15' x 4.5' | 11211-gal / (50895-ltr) | 18-kW | |