Convert ppm per degree Fahrenheit to Percent per kelvin
Convert ppm per degree Fahrenheit (ppm/°F) to Percent per kelvin (%/K) instantly and accurately.
Conversion Formula
%/K = ppm/°F × 0.00018
About ppm per degree Fahrenheit
The ppm/°F (= μin/(in·°F) exactly) equals 9/5 × 10⁻⁶ /K ≈1.8 × 10⁻⁶ /K and is the dominant CTE unit in US ASTM standards, ASME piping codes, and mechanical engineering handbooks. Steel ≈6.7 ppm/°F; aluminium ≈12.8 ppm/°F; copper ≈9.4 ppm/°F. 1 ppm/°F = 9/5 × 10⁻⁶ /K.
About Percent per kelvin
The %/K equals exactly 10⁻² /K = 10 000 ppm/K and is used for high-CTE materials such as polymers, foams, and rubber. PTFE: ≈0.0135 %/K; HDPE: ≈0.015 %/K; natural rubber: ≈0.06 %/K; silicone rubber: ≈0.10 %/K. 1 %/K = 10⁻² /K = 10 mm/(m·K) = 10 000 ppm/K.
Quick Reference Table
| ppm per degree Fahrenheit (ppm/°F) | Percent per kelvin (%/K) |
|---|---|
| 1 ppm/°F | 0.00018 %/K |
| 2 ppm/°F | 0.00036 %/K |
| 5 ppm/°F | 0.0009 %/K |
| 10 ppm/°F | 0.0018 %/K |
| 25 ppm/°F | 0.0045 %/K |
| 50 ppm/°F | 0.009 %/K |
| 100 ppm/°F | 0.018 %/K |