kW to BTU Converter
Formula: BTU/hr = kW × 3,412. Type a number to convert it, and see how much garage it would heat.
BTU/hr
17,060BTU/hr
As a heater, this delivers enough for about 400 sq ft of garage at average insulation on a 40°F rise. Check it in the garage heater calculator.
Kilowatts to BTU/hr chart
| Kilowatts | BTU/hr | Garage it can heat |
|---|---|---|
| 0.5 kW | 1,706 BTU/hr | Under 50 sq ft |
| 1 kW | 3,412 BTU/hr | 80 sq ft |
| 1.5 kW | 5,118 BTU/hr | 120 sq ft |
| 2 kW | 6,824 BTU/hr | 160 sq ft |
| 3 kW | 10,236 BTU/hr | 240 sq ft |
| 3.5 kW | 11,942 BTU/hr | 280 sq ft |
| 5 kW | 17,060 BTU/hr | 400 sq ft |
| 7.5 kW | 25,590 BTU/hr | 600 sq ft |
| 10 kW | 34,120 BTU/hr | 800 sq ft |
| 12 kW | 40,944 BTU/hr | 960 sq ft |
| 15 kW | 51,180 BTU/hr | 1,200 sq ft |
| 20 kW | 68,240 BTU/hr | 1,600 sq ft |
What this conversion means for a heater
One kilowatt is 1,000 watts, or about 3,412 BTU per hour. Larger electric heaters, heat pumps and boilers are often rated in kW, so this is the quickest way to compare them against a gas heater rated in BTU.
Ready to size a real heater? The garage heater calculator includes your climate and insulation.
Questions people ask
How many BTU is 1 kW?
About 3,412 BTU/hr.
How many BTU is 5 kW?
About 17,060 BTU/hr.
How many BTU is 10 kW?
About 34,120 BTU/hr.
What size garage will a 5 kW heater heat?
About 350 sq ft at average insulation, an 8 ft ceiling and a 40°F rise in our model.
Sources
Sources last checked October 31, 2026.
- EIA: British thermal units (accessed October 2026)