BTU per hour-ft² to watts per square meter
Type a value in BTU/(h·ft²) to get it in W/m² instantly.
3,154.591W/m²
That's 2.3× as bright as sunlight above the atmosphere — nothing on our list beats it. A two-square-meter panel at 20% would make about 1,262 W.
Convert the other way: W/m² to BTU/(h·ft²)
What it means
How much sun is that?
Panels are rated at 1,000 W/m², called one sun. kWh/m² per day here is averaged over 24 hours, not over daylight only.
The math
How to convert BTU/(h·ft²) to W/m²
To convert BTU per hour-ft² to watts per square meter, multiply by 3.15459.
Example: 1,000 BTU/(h·ft²) × 3.15459 = 3,154.59 W/m².
In the other direction, 1 W/m² = 0.316998 BTU/(h·ft²).
Every unit
Your irradiance in every unit
Tables
BTU/(h·ft²) to W/m² conversion table
| BTU/(h·ft²) | W/m² |
|---|---|
| 50 BTU/(h·ft²) | 157.73 W/m² |
| 100 BTU/(h·ft²) | 315.459 W/m² |
| 200 BTU/(h·ft²) | 630.918 W/m² |
| 400 BTU/(h·ft²) | 1,261.84 W/m² |
| 600 BTU/(h·ft²) | 1,892.75 W/m² |
| 800 BTU/(h·ft²) | 2,523.67 W/m² |
| 1,000 BTU/(h·ft²) | 3,154.59 W/m² |
| 1,200 BTU/(h·ft²) | 3,785.51 W/m² |
| 1,361 BTU/(h·ft²) | 4,293.4 W/m² |
| 1,500 BTU/(h·ft²) | 4,731.89 W/m² |
W/m² to BTU/(h·ft²) conversion table
| W/m² | BTU/(h·ft²) |
|---|---|
| 50 W/m² | 15.8499 BTU/(h·ft²) |
| 100 W/m² | 31.6998 BTU/(h·ft²) |
| 200 W/m² | 63.3997 BTU/(h·ft²) |
| 400 W/m² | 126.799 BTU/(h·ft²) |
| 600 W/m² | 190.199 BTU/(h·ft²) |
| 800 W/m² | 253.599 BTU/(h·ft²) |
| 1,000 W/m² | 316.998 BTU/(h·ft²) |
| 1,200 W/m² | 380.398 BTU/(h·ft²) |
| 1,361 W/m² | 431.435 BTU/(h·ft²) |
| 1,500 W/m² | 475.497 BTU/(h·ft²) |
Quick answers
Quick answers
- How many W/m² is 1 BTU/(h·ft²)?
- 1 BTU/(h·ft²) is 3.15459 W/m².
- How many W/m² is 10 BTU/(h·ft²)?
- 10 BTU/(h·ft²) is 31.5459 W/m².
- How many W/m² is 1,000 BTU/(h·ft²)?
- 1,000 BTU/(h·ft²) is 3,154.59 W/m².
The units
About these units
BTU per hour-ft² (BTU/(h·ft²))
The US form: one sun is about 317 BTU/h·ft².
Watts per square meter (W/m²)
The SI unit of irradiance. Full sun is about 1,000 W/m².
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