Per Degree Fahrenheit to Per Degree Celsius (°F⁻¹ to °C⁻¹)
1 per degree Fahrenheit (°F⁻¹) = 1.8 per degree Celsius (°C⁻¹). 1 °C⁻¹ = 0.5555555556 °F⁻¹. Example: 15 °F⁻¹ = 15 × 1.8 = 27 °C⁻¹.
Also searched as per degree Fahrenheit to °C⁻¹, per degree Fahrenheit in °C⁻¹, per degree Fahrenheit into per degree Celsius, °F⁻¹ to °C⁻¹, °F⁻¹ in per degree Celsius, °F⁻¹ into per degree Celsius, per degree Fahrenheit to per degree Celsius, °F⁻¹ to per degree Celsius converter and how many per degree Celsius in a per degree Fahrenheit.
1 °F⁻¹ = 1.8 °C⁻¹
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk per degree Fahrenheit to per degree Celsius converter to paste a column from Excel.
How to Convert Per Degree Fahrenheit to Per Degree Celsius
- 1 °F⁻¹ = 1.8 °C⁻¹
- 1 °C⁻¹ = 0.5555555556 °F⁻¹
- Example: convert 15 °F⁻¹ to °C⁻¹: 15 °F⁻¹ = 15 × 1.8 °C⁻¹ = 27 °C⁻¹
Formula
°C⁻¹ = °F⁻¹ × 1.8
Derivation from SI units:
- A Fahrenheit degree is 5/9 of a kelvin, so 1/°F = 1.8/K (exact)
- 1/°C = 1/K, because a temperature difference of 1 °C equals 1 K
- 1 °F⁻¹ = 1.8 K⁻¹ ÷ 1 K⁻¹ per °C⁻¹ = 1.8 °C⁻¹
Both units are defined exactly, so the factor is exact. Per Degree Fahrenheit definition: per degree Fahrenheit; Per Degree Celsius definition: per degree Celsius.
Worked examples
- A reading of 0.0000065 °F⁻¹ converts to 0.0000117 °C⁻¹.
0.0000065 °F⁻¹ × 1.8 = 0.0000117 °C⁻¹ - A value of 0.00003 °F⁻¹ is 0.000054 °C⁻¹.
0.00003 °F⁻¹ × 1.8 = 0.000054 °C⁻¹
Per Degree Fahrenheit to Per Degree Celsius conversion table
| Per Degree Fahrenheit (°F⁻¹) | Per Degree Celsius (°C⁻¹) |
|---|---|
| 0.0000003 °F⁻¹ | 5.4 × 10⁻⁷ °C⁻¹ |
| 0.0000005 °F⁻¹ | 9 × 10⁻⁷ °C⁻¹ |
| 0.000005 °F⁻¹ | 0.000009 °C⁻¹ |
| 0.0000065 °F⁻¹ | 0.0000117 °C⁻¹ |
| 0.0000096 °F⁻¹ | 0.00001728 °C⁻¹ |
| 0.0000128 °F⁻¹ | 0.00002304 °C⁻¹ |
| 0.00003 °F⁻¹ | 0.000054 °C⁻¹ |
| 0.00005 °F⁻¹ | 0.00009 °C⁻¹ |
| 0.0001 °F⁻¹ | 0.00018 °C⁻¹ |
| 0.0005 °F⁻¹ | 0.0009 °C⁻¹ |
Where it's used
Per Degree Fahrenheit are used for US piping and structural codes (ASME B31, AISC), 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.
Per Degree Fahrenheit to other thermal expansion coefficient units
| Conversion | 1 °F⁻¹ equals |
|---|---|
| per degree Fahrenheit to per degree Celsius | 1.8 °C⁻¹ |
| per degree Fahrenheit to per kelvin | 1.8 K⁻¹ |
| per degree Fahrenheit to ppm per kelvin | 1800000 ppm/K |
| per degree Fahrenheit to ppm per degree Fahrenheit | 1000000 ppm/°F |
Frequently asked questions
How many per degree Celsius are in 1 per degree Fahrenheit?
1 °F⁻¹ = 1.8 °C⁻¹.
How do I convert per degree Fahrenheit to per degree Celsius?
Multiply the value in °F⁻¹ by 1.8. For example, 15 °F⁻¹ × 1.8 = 27 °C⁻¹.
Is the °F⁻¹ to °C⁻¹ conversion exact?
Yes. Both units are defined exactly, and 1 °F⁻¹ is exactly 1.8 °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). Per Degree Fahrenheit to Per Degree Celsius (°F⁻¹ to °C⁻¹). Retrieved October 25, 2026, from https://scientificconverters.com/thermal-expansion/per-degree-fahrenheit-to-per-degree-celsius/
IEEE
Scientific Converters, "Per Degree Fahrenheit to Per Degree Celsius (°F⁻¹ to °C⁻¹)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/thermal-expansion/per-degree-fahrenheit-to-per-degree-celsius/