Convert ppm/°F to Per Degree Celsius (ppm/°F to °C⁻¹)
1 ppm per degree Fahrenheit (ppm/°F) = 0.0000018 per degree Celsius (°C⁻¹). 1 °C⁻¹ = 555555.5556 ppm/°F. Example: 15 ppm/°F = 15 × 0.0000018 = 0.000027 °C⁻¹.
Also searched as ppm per degree Fahrenheit to °C⁻¹, ppm per degree Fahrenheit in °C⁻¹, ppm per degree Fahrenheit into per degree Celsius, ppm/°F to °C⁻¹, ppm/°F in per degree Celsius, ppm/°F into per degree Celsius, ppm per degree Fahrenheit to per degree Celsius, ppm/°F to per degree Celsius converter and how many per degree Celsius in a ppm per degree Fahrenheit.
1 ppm/°F = 0.0000018 °C⁻¹
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk ppm per degree Fahrenheit to per degree Celsius converter to paste a column from Excel.
How to Convert ppm/°F to Per Degree Celsius
- 1 ppm/°F = 0.0000018 °C⁻¹
- 1 °C⁻¹ = 555555.5556 ppm/°F
- Example: convert 15 ppm/°F to °C⁻¹: 15 ppm/°F = 15 × 0.0000018 °C⁻¹ = 0.000027 °C⁻¹
Formula
°C⁻¹ = ppm/°F × 0.0000018
or °C⁻¹ = ppm/°F ÷ 555555.5555556
Derivation from SI units:
- 1 ppm/°F = 10⁻⁶ /°F = 1.8 × 10⁻⁶ K⁻¹ = 1 µin/(in·°F)
- 1/°C = 1/K, because a temperature difference of 1 °C equals 1 K
- 1 ppm/°F = 0.0000018 K⁻¹ ÷ 1 K⁻¹ per °C⁻¹ = 0.0000018 °C⁻¹
Both units are defined exactly, so the factor is exact. ppm/°F definition: ppm per degree Fahrenheit; Per Degree Celsius definition: per degree Celsius.
Worked examples
- A reading of 5 ppm/°F converts to 0.000009 °C⁻¹.
5 ppm/°F × 0.0000018 = 0.000009 °C⁻¹ - A value of 9.6 ppm/°F is 0.00001728 °C⁻¹.
9.6 ppm/°F × 0.0000018 = 0.00001728 °C⁻¹
ppm/°F to Per Degree Celsius conversion table
| ppm/°F | Per Degree Celsius (°C⁻¹) |
|---|---|
| 0.3 ppm/°F | 5.4 × 10⁻⁷ °C⁻¹ |
| 1 ppm/°F | 0.0000018 °C⁻¹ |
| 3 ppm/°F | 0.0000054 °C⁻¹ |
| 5 ppm/°F | 0.000009 °C⁻¹ |
| 6.5 ppm/°F | 0.0000117 °C⁻¹ |
| 7 ppm/°F | 0.0000126 °C⁻¹ |
| 9.6 ppm/°F | 0.00001728 °C⁻¹ |
| 12.8 ppm/°F | 0.00002304 °C⁻¹ |
| 20 ppm/°F | 0.000036 °C⁻¹ |
| 50 ppm/°F | 0.00009 °C⁻¹ |
Where it's used
ppm/°F are used for US material and alloy datasheets, while per degree Celsius appear in engineering handbooks and material tables. Both measure coefficient of thermal expansion (α, CTE), so the conversion is a fixed factor.
ppm/°F to other thermal expansion coefficient units
| Conversion | 1 ppm/°F equals |
|---|---|
| ppm per degree Fahrenheit to per degree Celsius | 0.0000018 °C⁻¹ |
| ppm per degree Fahrenheit to per kelvin | 0.0000018 K⁻¹ |
| ppm per degree Fahrenheit to ppm per kelvin | 1.8 ppm/K |
| ppm per degree Fahrenheit to per degree Fahrenheit | 0.000001 °F⁻¹ |
Frequently asked questions
How many per degree Celsius are in 1 ppm per degree Fahrenheit?
1 ppm/°F = 0.0000018 °C⁻¹.
How do I convert ppm per degree Fahrenheit to per degree Celsius?
Multiply the value in ppm/°F by 0.0000018, or divide it by 555555.5556. For example, 15 ppm/°F × 0.0000018 = 0.000027 °C⁻¹.
Is the ppm/°F to °C⁻¹ conversion exact?
Yes. Both units are defined exactly, and 1 ppm/°F is exactly 0.0000018 °C⁻¹.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "degree Fahrenheit".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, degree Celsius.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert ppm/°F to Per Degree Celsius (ppm/°F to °C⁻¹). Retrieved October 25, 2026, from https://scientificconverters.com/thermal-expansion/ppm-per-degree-fahrenheit-to-per-degree-celsius/
IEEE
Scientific Converters, "Convert ppm/°F to Per Degree Celsius (ppm/°F to °C⁻¹)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/thermal-expansion/ppm-per-degree-fahrenheit-to-per-degree-celsius/