Infrared Heater Wattage Guide
Find the right infrared heater size for your room, garage, or outdoor space. Avoid underpowered or oversized units with this free US sizing guide.
Use 10 watts per square foot as a baseline for infrared heaters. A 150 sq ft room needs ~1,500W. A 300 sq ft room needs ~3,000W. Add 25% for poorly insulated spaces or outdoor use.
Infrared Heater Size Guide by Room Size (US 2026)
| Space | Sq Ft | Watts Needed | Recommended Model |
|---|---|---|---|
| Small bedroom | 100 | 750–1,000W | 750W–1,000W unit |
| Medium bedroom | 150 | 1,000–1,500W | 1,500W unit |
| Living room | 250 | 2,000–2,500W | 2,000W unit |
| Large room | 300 | 2,500–3,000W | 3,000W unit |
| 1-Car garage | 250 | 2,500–3,000W | 3,000W unit |
| 2-Car garage | 500 | 4,000–5,000W | Dual 2,500W units |
| Outdoor patio | 150 | 1,500–2,000W | 1,500W outdoor unit |
Add 25% for poor insulation or outdoor spaces exposed to wind.
Calculate the Right Infrared Heater Size
How to Choose the Right Infrared Heater Wattage
The standard rule for infrared heaters is 10 watts per square foot for a well-insulated indoor space. A 150 sq ft bedroom needs roughly 1,500W. A 300 sq ft living room needs around 3,000W for comfortable warmth at typical US winter temperatures.
Outdoor and garage spaces need 25–60% more wattage than indoor rooms because heat dissipates into open air rather than being contained by walls. A 150 sq ft covered patio needs 2,000–2,500W compared to 1,500W for an equivalent indoor room.
For large garages and workshops consider using multiple smaller infrared heaters rather than one large unit. Two 2,500W heaters positioned at opposite ends of a 500 sq ft garage distribute heat more evenly than a single 5,000W unit mounted in one location. See our infrared heater cost calculator to estimate your running costs.