Watt per square meter to BTU per hour square foot Converter
1 watt per square meter is about 0.3169983306 BTUs per hour square foot. Convert watts per square meter (W/m²) to BTUs per hour square foot (BTU/(h·ft²)) below: type a value and the result updates as you type.
W/m² to BTU/(h·ft²) calculator
Result
Watt per square meter to BTU per hour square foot conversion
1 W/m² ≈ 0.3169983306 BTU/(h·ft²)one watt per square meter in BTUs per hour square foot
1 BTU/(h·ft²) ≈ 3.154590745 W/m²one BTU per hour square foot in watts per square meter
Watt per square meter (W/m²): SI unit of heat flux density and irradiance. Full sunlight at ground level is roughly 1000 W/m².
BTU per hour square foot (BTU/(h·ft²)): One BTU (IT) per hour through one square foot.
Source:Watt per square meter: SI Brochure, 9th edition (BIPM, 2019); BTU per hour square foot: NIST Special Publication 811 (2008), Appendix B.8
How to convert watts per square meter to BTUs per hour square foot
To convert watts per square meter to BTUs per hour square foot, multiply the number of watts per square meter by about 0.3169983306.
Formula
BTU/(h·ft²) = W/m² × 0.3169983306
The factor is rounded here. The calculator uses the exact value.
Examples
- 5 W/m² = 5 × 0.3169983306 ≈ 1.584991653 BTU/(h·ft²)
- 25 W/m² = 25 × 0.3169983306 ≈ 7.924958266 BTU/(h·ft²)
- 100 W/m² = 100 × 0.3169983306 ≈ 31.69983306 BTU/(h·ft²)
Watt per square meter to BTU per hour square foot conversion table
| Watt per square meter (W/m²) | BTU per hour square foot (BTU/(h·ft²)) |
|---|---|
| 0.1 W/m² | 0.03169983306 BTU/(h·ft²) |
| 0.5 W/m² | 0.1584991653 BTU/(h·ft²) |
| 1 W/m² | 0.3169983306 BTU/(h·ft²) |
| 2 W/m² | 0.6339966613 BTU/(h·ft²) |
| 3 W/m² | 0.9509949919 BTU/(h·ft²) |
| 5 W/m² | 1.584991653 BTU/(h·ft²) |
| 10 W/m² | 3.169983306 BTU/(h·ft²) |
| 20 W/m² | 6.339966613 BTU/(h·ft²) |
| 25 W/m² | 7.924958266 BTU/(h·ft²) |
| 50 W/m² | 15.84991653 BTU/(h·ft²) |
| 100 W/m² | 31.69983306 BTU/(h·ft²) |
| 250 W/m² | 79.24958266 BTU/(h·ft²) |
| 500 W/m² | 158.4991653 BTU/(h·ft²) |
| 1000 W/m² | 316.9983306 BTU/(h·ft²) |
Values rounded to 10 significant digits where needed.
Frequently asked questions
- How many BTUs per hour square foot are in one watt per square meter?
- One watt per square meter is about 0.3169983306 BTUs per hour square foot.
- How do I convert BTUs per hour square foot to watts per square meter?
- To convert BTUs per hour square foot to watts per square meter, multiply the number of BTUs per hour square foot by about 3.154590745. The formula is W/m² = BTU/(h·ft²) × 3.154590745.
- Is this conversion exact?
- Yes. Both units have exact definitions, but the factor has more decimal places than can be shown, so displayed results are rounded. The calculator works with 50 significant digits before rounding.
- Which is larger, a watt per square meter or a BTU per hour square foot?
- A BTU per hour square foot is about 3.154590745 times larger than a watt per square meter. In other words, a watt per square meter is about 0.3169983306 of a BTU per hour square foot.