Popular heat density conversions
- Joules per square meter to kilowatt-hours per square meter1 J/m² = 2.77778×10⁻⁷ kWh/m²
- Joules per square meter to langleys1 J/m² = 0.0000239006 Ly
- Joules per square meter to BTU per square foot1 J/m² = 0.0000880551 BTU/ft²
- Kilowatt-hours per square meter to joules per square meter1 kWh/m² = 3,600,000 J/m²
- Kilowatt-hours per square meter to langleys1 kWh/m² = 86.0421 Ly
- Kilowatt-hours per square meter to BTU per square foot1 kWh/m² = 316.998 BTU/ft²
- Langleys to joules per square meter1 Ly = 41,840 J/m²
- Langleys to kilowatt-hours per square meter1 Ly = 0.0116222 kWh/m²
- Langleys to BTU per square foot1 Ly = 3.68423 BTU/ft²
- BTU per square foot to joules per square meter1 BTU/ft² = 11,356.5 J/m²
- BTU per square foot to kilowatt-hours per square meter1 BTU/ft² = 0.00315459 kWh/m²
- BTU per square foot to langleys1 BTU/ft² = 0.271428 Ly
About heat density units
Heat density (radiant exposure) is energy per unit area. Solar energy researchers use kWh/m² per day; the langley (1 thermochemical cal/cm²) is a traditional solar-radiation unit.
Heat Density unit reference
| Unit | Symbol | Value in J/m² | System |
|---|---|---|---|
| Joule per square meter | J/m² | 1 J/m² | SI |
| Kilojoule per square meter | kJ/m² | 1,000 J/m² | SI |
| Megajoule per square meter | MJ/m² | 1,000,000 J/m² | SI |
| Watt-hour per square meter | Wh/m² | 3,600 J/m² | Metric |
| Kilowatt-hour per square meter | kWh/m² | 3,600,000 J/m² | Metric |
| Langley | Ly | 41,840 J/m² | Other |
| BTU per square foot | BTU/ft² | 11,356.527 J/m² | US customary |
Frequently asked questions
What is the SI unit of heat density?
This converter uses the joule per square meter (J/m²) as its reference unit; every other unit is defined relative to it.
How many heat density units can I convert?
7 units are supported here, across SI, Metric, Other, US customary systems. Every pair can be converted in both directions.
Does this heat density converter work offline?
Yes. Once the page has loaded, every calculation runs locally in your browser — nothing is sent to a server.