Thermal conductivity converter
Thermal conductivity Converter – 6 Units, Exact Factors
1 watt per metre kelvin = 0.57779 BTU per hour foot °F
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- 1 W/(m·K) = 0.57779 BTU/(h·ft·°F)
- 5 W/(m·K) = 2.8889 BTU/(h·ft·°F)
- 10 W/(m·K) = 5.7779 BTU/(h·ft·°F)
- 25 W/(m·K) = 14.445 BTU/(h·ft·°F)
- Watts per metre kelvinW/(m·K)
- Watts per centimetre kelvinW/(cm·K)
- BTU per hour foot °FBTU/(h·ft·°F)
- BTU inch per hour square foot °FBTU·in/(h·ft²·°F)
- Kilocalories (IT) per hour metre °Ckcal_IT/(h·m·°C)
- Calories (th) per second centimetre °Ccal_th/(s·cm·°C)
- Watts per metre kelvin1W/(m·K)
- Watts per centimetre kelvin0.01W/(cm·K)
- BTU per hour foot °F0.57779BTU/(h·ft·°F)
- BTU inch per hour square foot °F6.9335BTU·in/(h·ft²·°F)
- Kilocalories (IT) per hour metre °C0.85985kcal_IT/(h·m·°C)
- Calories (th) per second centimetre °C0.0023901cal_th/(s·cm·°C)
About thermal conductivity conversions
How well a material conducts heat (k-value). The degree in these units is a temperature difference, so 1 K and 1 °C are the same step, and 1 °F is 5/9 of it.
Common thermal conductivity conversions
Thermal conductivity units explained
| Unit | System | Definition and notes |
|---|---|---|
| Watt per metre kelvin (W/(m·K)) | SI (metric) | Base unitThe SI unit of thermal conductivity. Copper is about 400, steel is about 50, mineral wool is about 0.04 W/(m·K). |
| Watt per centimetre kelvin (W/(cm·K)) | SI (metric) | 1 W/(cm·K) = 100 W/(m·K) (exact) |
| BTU per hour foot °F (BTU/(h·ft·°F)) | US & imperial (identical) | 1 BTU/(h·ft·°F) ≈ 1.7307347 W/(m·K)BTU per hour per foot per °F, about 1.7307 W/(m·K). The °F here is a temperature difference. |
| BTU inch per hour square foot °F (BTU·in/(h·ft²·°F)) | US & imperial (identical) | 1 BTU·in/(h·ft²·°F) ≈ 0.14422789 W/(m·K)The US insulation k-value unit, about 0.14423 W/(m·K). |
| Kilocalorie (IT) per hour metre °C (kcal_IT/(h·m·°C)) | other | 1 kcal_IT/(h·m·°C) = 1.163 W/(m·K) (exact)Kilocalories per hour per metre per °C: exactly 1.163 W/(m·K). |
| Calorie (th) per second centimetre °C (cal_th/(s·cm·°C)) | other | 1 cal_th/(s·cm·°C) = 418.4 W/(m·K) (exact)Calories per second per centimetre per °C (chemistry calorie): exactly 418.4 W/(m·K). |
Watts per metre kelvin to BTU per hour foot °F conversion table
| Watts per metre kelvin (W/(m·K)) | BTU per hour foot °F (BTU/(h·ft·°F)) |
|---|---|
| 0.025 W/(m·K) | 0.014445 BTU/(h·ft·°F) |
| 0.04 W/(m·K) | 0.023112 BTU/(h·ft·°F) |
| 0.1 W/(m·K) | 0.057779 BTU/(h·ft·°F) |
| 0.5 W/(m·K) | 0.28889 BTU/(h·ft·°F) |
| 1 W/(m·K) | 0.57779 BTU/(h·ft·°F) |
| 1.5 W/(m·K) | 0.86668 BTU/(h·ft·°F) |
| 15 W/(m·K) | 8.6668 BTU/(h·ft·°F) |
| 50 W/(m·K) | 28.889 BTU/(h·ft·°F) |
| 100 W/(m·K) | 57.779 BTU/(h·ft·°F) |
| 200 W/(m·K) | 115.56 BTU/(h·ft·°F) |
| 237 W/(m·K) | 136.94 BTU/(h·ft·°F) |
| 400 W/(m·K) | 231.12 BTU/(h·ft·°F) |
Frequently asked questions
Which thermal conductivity units can I convert?
watts per metre kelvin (W/(m·K)), watts per centimetre kelvin (W/(cm·K)), BTU per hour foot °F (BTU/(h·ft·°F)), BTU inch per hour square foot °F (BTU·in/(h·ft²·°F)), kilocalories (IT) per hour metre °C (kcal_IT/(h·m·°C)), calories (th) per second centimetre °C (cal_th/(s·cm·°C)).
How accurate are the results?
Every unit is stored with its exact defining factor (NIST SP 811, NIST Handbook 44 or the BIPM SI Brochure). Calculations use double-precision arithmetic and are rounded only for display, to 5 significant figures by default (trailing zeros dropped, so 1 km shows as 1000 m). You can choose Auto (up to 10 digits), fixed decimals or more significant figures, or switch to scientific or engineering notation.
Why do °C, K and °F appear without an offset here?
In these units the temperature is a temperature difference (an interval), not a reading. A difference of 1 K equals 1 °C and 1 °F equals 5/9 K, so only the scale factor applies and the 32° or 273.15° offset never does.