Convert between BTU/hr and Watts instantly — bidirectional with HVAC reference
Formulas:
Watts = BTU/hr × 0.293071
BTU/hr = Watts × 3.41214
1 BTU/hr = 0.293071 W = 0.000293071 kW
| Appliance / Use | BTU/hr | Watts | kW |
|---|---|---|---|
| Small room AC (150 sq ft) | 5,000 | 1,465 | 1.47 |
| Medium room AC (350 sq ft) | 8,000 | 2,345 | 2.34 |
| Large room AC (550 sq ft) | 12,000 | 3,517 | 3.52 |
| Portable heater | 5,120 | 1,500 | 1.50 |
| Central AC (1 ton) | 12,000 | 3,517 | 3.52 |
| Central AC (2 ton) | 24,000 | 7,034 | 7.03 |
| Central AC (3 ton) | 36,000 | 10,550 | 10.55 |
| Central AC (5 ton) | 60,000 | 17,584 | 17.58 |
| Mini-split unit | 9,000 | 2,638 | 2.64 |
| Furnace (small) | 40,000 | 11,723 | 11.72 |
Multiply BTU/hr by 0.293071 to get Watts. For example, 10,000 BTU/hr × 0.293071 = 2,930.71 Watts. To convert back, multiply Watts by 3.41214.
BTU (British Thermal Unit) is a unit of heat energy commonly used in HVAC. 1 BTU is the energy needed to raise 1 pound of water by 1°F. BTU/hr measures the rate of heating or cooling.
General rule: 20 BTU per square foot. A 200 sq ft room needs ~4,000 BTU, a 500 sq ft room ~10,000 BTU. Adjust for sun exposure, insulation quality, ceiling height, and climate zone.