Convert thermal conductivity between W/(m·K), BTU/(h·ft·°F), kcal/(h·m·°C) and more — instant, animated, with a full reference table.
Heat • 7 units
Built on internationally recognised SI and standards-body conversion factors for dependable results.
Results update live as you type, with a clear visual breakdown across every unit at once.
Everything runs in your browser — no account, no uploads, nothing leaves your device.
Thermal conductivity describes how readily a material lets heat pass through it. The concept dates to Joseph Fourier, whose 1822 Théorie analytique de la chaleur set out the law of heat conduction still used today. The modern SI unit, the watt per metre-kelvin, W/(m·K), expresses how many watts flow through a one-metre thickness of material for each kelvin of temperature difference.
Engineers and builders use thermal conductivity constantly: choosing insulation (low values trap heat), sizing heat sinks for electronics (high values such as copper or aluminium move heat away), specifying cookware, and modelling how buildings gain or lose energy. In the US, conductivity is often quoted in BTU/(h·ft·°F) or as the related "k-value" on insulation products, while the rest of the world uses W/(m·K) — making conversion a frequent need.
Quick reference — 1 Watt/meter·K (W/(m·K)) is equal to:
| Watt/centimeter·°C | W/(cm·°C) | 0.01 |
| Kilowatt/meter·K | kW/(m·K) | 0.001 |
| Calorie/(s·cm·°C) | cal/(s·cm·°C) | 0.0023900574 |
| Kilocalorie/(h·m·°C) | kcal/(h·m·°C) | 0.859845228 |
| BTU/(h·ft·°F) | BTU/(h·ft·°F) | 0.577789205 |
| BTU·in/(h·ft²·°F) | BTU·in/(h·ft²·°F) | 6.933471 |