21 Watt/Meter-Kelvin to BTU/Hour-Foot-°F
Quick answer
21 Watt/Meter-Kelvin (W/(m·K)) equals
12.133576 BTU/(h·ft·°F)
To convert 21 Watt/Meter-Kelvins to BTU/Hour-Foot-°Fs, multiply by 0.5777893167. Therefore, 21 Watt/Meter-Kelvin (W/(m·K)) equals 12.133576 BTU/Hour-Foot-°F (BTU/(h·ft·°F)).
Formula: BTU/(h·ft·°F) = W/(m·K) × 0.5777893167. Calculation: 21 × 0.5777893167 = 12.133576 BTU/(h·ft·°F).
Convert Watt/Meter-Kelvin (W/(m·K)) to BTU/Hour-Foot-°F (BTU/(h·ft·°F)) online with our free unit converter. In thermal conductivity, 1 W/(m·K) = 0.577789 BTU/(h·ft·°F). Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Watt/Meter-Kelvin to BTU/Hour-Foot-°F
- Step 1 — start with the formula. BTU/(h·ft·°F) = W/(m·K) × 0.5777893167
- Step 2 — substitute your figure. 21 W/(m·K) × 0.5777893167
- Step 3 — read the result. 21 W/(m·K) = 12.133576 BTU/(h·ft·°F)
- Step 4 — check it in reverse. W/(m·K) = BTU/(h·ft·°F) × 1.730734666 returns 21 W/(m·K), which matches the figure you started with.
Thermal Conductivity Converter
7 units available
21 W/(m·K) = 12.133576 BTU/(h·ft·°F)
Formula:
BTU/(h·ft·°F) = W/(m·K) × 0.5777893167With your value: 21 W/(m·K) = 12.13357565 BTU/(h·ft·°F)
Other Watt/Meter-Kelvin to BTU/Hour-Foot-°F conversions
Watt/Meter-Kelvin to BTU/Hour-Foot-°F Conversion Table
| Watt/Meter-Kelvin (W/(m·K)) | BTU/Hour-Foot-°F (BTU/(h·ft·°F)) |
|---|---|
| 0.5 | 0.288895 |
| 1 | 0.577789 |
| 2 | 1.155579 |
| 5 | 2.888947 |
| 10 | 5.777893 |
| 15 | 8.66684 |
| 20 | 11.555786 |
| 25 | 14.444733 |
| 50 | 28.889466 |
| 100 | 57.778932 |
| 250 | 144.447329 |
| 500 | 288.894658 |
| 1000 | 577.789317 |
BTU/Hour-Foot-°F to Watt/Meter-Kelvin Conversion Table
| BTU/Hour-Foot-°F (BTU/(h·ft·°F)) | Watt/Meter-Kelvin (W/(m·K)) |
|---|---|
| 0.5 | 0.865367 |
| 1 | 1.730735 |
| 2 | 3.461469 |
| 5 | 8.653673 |
| 10 | 17.307347 |
| 15 | 25.96102 |
| 20 | 34.614693 |
| 25 | 43.268367 |
| 50 | 86.536733 |
| 100 | 173.073467 |
| 250 | 432.683667 |
| 500 | 865.367333 |
| 1000 | 1,730.734666 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Watt/Meter-Kelvin (W/(m·K))
Thermal Conductivity
Derived quantity, watt per metre-kelvin (W/(m·K)). Imperial and calorie-based units convert exactly via the thermochemical calorie and the international BTU.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
BTU/Hour-Foot-°F (BTU/(h·ft·°F))
Thermal Conductivity
Derived quantity, watt per metre-kelvin (W/(m·K)). Imperial and calorie-based units convert exactly via the thermochemical calorie and the international BTU.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
How to Convert Watt/Meter-Kelvin to BTU/Hour-Foot-°F
To convert from Watt/Meter-Kelvin (W/(m·K)) to BTU/Hour-Foot-°F (BTU/(h·ft·°F)), multiply the value by 0.5777893167.
Formula: BTU/(h·ft·°F) = W/(m·K) × 0.5777893167
Reverse: W/(m·K) = BTU/(h·ft·°F) × 1.730734666
Step-by-Step Example
- Start with your value in Watt/Meter-Kelvin. For example: 5 W/(m·K)
- Multiply by the conversion factor: 5 x 0.5777893167
- The result is: 2.888947 BTU/(h·ft·°F)
Watt/Meter-Kelvin and BTU/Hour-Foot-°F Relationship
This conversion bridges the Metric (SI) and US Customary / Imperial measurement systems, commonly required when translating scientific data, international engineering specifications, or trade standards. Since 1 Watt/Meter-Kelvin represents a fraction of a BTU/Hour-Foot-°F (1 BTU/Hour-Foot-°F ≈ 1.7307 Watt/Meter-Kelvins), the BTU/Hour-Foot-°F is the larger measurement interval. Understanding the relationship between Watt/Meter-Kelvin and BTU/Hour-Foot-°F is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Watt/Meter-Kelvin
The Watt/Meter-Kelvin (symbol: W/(m·K)) is a recognized unit in the Metric (SI) measurement framework, utilized within thermal conductivity applications for precision and standardized data representation.
Common uses of Watt/Meter-Kelvin: thermal conductivity calculations, engineering and science, education.
About BTU/Hour-Foot-°F
The BTU/Hour-Foot-°F (symbol: BTU/(h·ft·°F)) is a recognized unit in the US Customary / Imperial measurement framework, utilized within thermal conductivity applications for precision and standardized data representation.
Common uses of BTU/Hour-Foot-°F: thermal conductivity calculations, engineering and science, education.
Frequently Asked Questions
- What is 21 Watt/Meter-Kelvin in BTU/Hour-Foot-°F?
- 21 Watt/Meter-Kelvin equals 12.133576 BTU/Hour-Foot-°F.
- How many BTU/Hour-Foot-°Fs are in 1 Watt/Meter-Kelvin?
- There are exactly 0.5777893167 BTU/Hour-Foot-°Fs in 1 Watt/Meter-Kelvin. This means the conversion factor from Watt/Meter-Kelvin to BTU/Hour-Foot-°F is 0.5777893167.
- What is the formula to convert Watt/Meter-Kelvin to BTU/Hour-Foot-°F?
- The formula to convert Watt/Meter-Kelvin to BTU/Hour-Foot-°F is: BTU/(h·ft·°F) = W/(m·K) × 0.5777893167. For example, to convert 10 Watt/Meter-Kelvins to BTU/Hour-Foot-°Fs, you would multiply 10 by 0.5777893167.
- What is a Watt/Meter-Kelvin?
- The Watt/Meter-Kelvin (symbol: W/(m·K)) is a recognized unit in the Metric (SI) measurement framework, utilized within thermal conductivity applications for precision and standardized data representation.
- What is a BTU/Hour-Foot-°F?
- The BTU/Hour-Foot-°F (symbol: BTU/(h·ft·°F)) is a recognized unit in the US Customary / Imperial measurement framework, utilized within thermal conductivity applications for precision and standardized data representation.
- What are the common uses of Watt/Meter-Kelvin?
- The Watt/Meter-Kelvin is commonly used in thermal conductivity calculations, engineering and science, education.
Related Thermal Conductivity Conversions
Cite this page
UnitConvertLab. (2026). 21 Watt/Meter-Kelvin to BTU/Hour-Foot-°F. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/21-watt_per_meter_k-to-btu_per_h_ft_f