How to use it
- Type a number. A dot or a comma works as the decimal separator.
- Choose the unit you have and the unit you need. The ⇄ button swaps them.
- The table shows the same conductivity in all common units at once.
Conversion factors
Every unit is converted through W/(m·K).
| Unit | In W/(m·K) |
|---|---|
| 1 W/(cm·K) | 100 |
| 1 kcal/(h·m·°C) | 1.163 |
| 1 cal/(s·cm·°C) | 418.68 |
| 1 BTU·in/(h·ft²·°F) | 0.14422789 |
| 1 BTU/(h·ft·°F) | 1.73073467 |
The BTU factors use 1,055.05585262 J, a foot of 0.3048 m, an inch of 0.0254 m and a Fahrenheit degree of 5/9 K.
Worked example
A foam board is listed at 0.03 W/(m·K). In US units that is 0.03 × 6.9334718 = 0.208 BTU·in/(h·ft²·°F). A material of 0.5 BTU·in/(h·ft²·°F) is 0.5 × 0.14422789 = 0.0721 W/(m·K).
Tips
- Lower conductivity means better insulation.
- Conductivity changes with temperature and moisture; data sheets quote it at a mean temperature.