Reference sheet
Heat flux conversion chart
W/m², BTU/(h·ft²). Factors are given to 7 significant figures; open the converter for full precision and the worked solution.
| Unit | In W/m² | 1 W/m² in unit |
|---|---|---|
| watt per square metre (W/m²) | 1 W/m² | 1 W/m² |
| kilowatt per square metre (kW/m²) | 1,000 W/m² | 0.001 kW/m² |
| watt per square centimetre (W/cm²) | 10,000 W/m² | 0.0001 W/cm² |
| BTU per hour square foot (BTU/(h·ft²)) | 3.154591 W/m² | 0.3169983 BTU/(h·ft²) |
| kilocalorie (IT) per hour square metre (kcal_IT/(h·m²)) | 1.163 W/m² | 0.8598452 kcal_IT/(h·m²) |
| W/m² | BTU/(h·ft²) |
|---|---|
| 0.1 W/m² | 0.03169983 BTU/(h·ft²) |
| 0.5 W/m² | 0.1584992 BTU/(h·ft²) |
| 1 W/m² | 0.3169983 BTU/(h·ft²) |
| 2 W/m² | 0.6339967 BTU/(h·ft²) |
| 5 W/m² | 1.584992 BTU/(h·ft²) |
| 10 W/m² | 3.169983 BTU/(h·ft²) |
| 20 W/m² | 6.339967 BTU/(h·ft²) |
| 25 W/m² | 7.924958 BTU/(h·ft²) |
| 50 W/m² | 15.84992 BTU/(h·ft²) |
| 100 W/m² | 31.69983 BTU/(h·ft²) |
| 250 W/m² | 79.24958 BTU/(h·ft²) |
| 500 W/m² | 158.4992 BTU/(h·ft²) |
| 1,000 W/m² | 316.9983 BTU/(h·ft²) |
| BTU/(h·ft²) | W/m² |
|---|---|
| 0.1 BTU/(h·ft²) | 0.3154591 W/m² |
| 0.5 BTU/(h·ft²) | 1.577295 W/m² |
| 1 BTU/(h·ft²) | 3.154591 W/m² |
| 2 BTU/(h·ft²) | 6.309181 W/m² |
| 5 BTU/(h·ft²) | 15.77295 W/m² |
| 10 BTU/(h·ft²) | 31.54591 W/m² |
| 20 BTU/(h·ft²) | 63.09181 W/m² |
| 25 BTU/(h·ft²) | 78.86477 W/m² |
| 50 BTU/(h·ft²) | 157.7295 W/m² |
| 100 BTU/(h·ft²) | 315.4591 W/m² |
| 250 BTU/(h·ft²) | 788.6477 W/m² |
| 500 BTU/(h·ft²) | 1,577.295 W/m² |
| 1,000 BTU/(h·ft²) | 3,154.591 W/m² |
Formula: BTU/(h·ft²) = W/m² × 0.3169983306
Need another value? Use the W/m² to BTU/(h·ft²) converter or the heat flux converter.
Unitglide · unitglide.app/reference/heat-flux · Factors from NIST SP 811, NIST Handbook 44 and the BIPM SI Brochure (9th ed.). Values rounded to 7 significant figures unless exact.