Formula – How to convert Fahrenheit (°F) to Kelvin (K)
K = (°F + 459.67) ÷ 1.8
- Step 1: add 459.67 to the temperature in Fahrenheit.
- Step 2: divide by 1.8
Find 70°F in Kelvin:
- Step 1: add 459.67 to the temperature in Fahrenheit: 70 + 459.67 = 529.67
- Step 2: divide by 1.8: 529.67 ÷ 1.8 = 294.26
What is the difference between Fahrenheit and Kelvin?
Fahrenheit is benchmarked between the freezing point of water (32°F, or 273.15K) and the boiling point of water (212°F, or 373.15K).
Kelvin is benchmarked from the temperature Absolute 0, the coldest temperature possible in the universe. It increases at the same interval as the celsius scale.
Unlike Celsius, Fahrenheit, and Rankine, Kelvin does not use a degree scale (°). The units of temperature in kelvin are simply noted as “K” not “°K”
Who uses Fahrenheit and Kelvin?
Fahrenheit is a common temperature scale (along with Fahrenheit) for temperature measurements, specifically weather. It is commonly used in the United States and parts of the Pacific and the Caribbean.
Kelvin is used in the scientific community, specifically the physical sciences.
What are other common temperature scales?
Celsius and Rankine are two other common temperature scales.
Celsius uses a scale of 0°C for the freezing point of water and 100°C for the boiling point of water. It follows the same temperature interval as Kelvin (an increase of 1°C is equivalent to an increase of 1K).
Rankine is related to Fahrenheit the same way that Kelvin is to Celsius. 0°R (0 degrees Rankine) is absolute 0, and the scale increases at the same interval as Fahrenheit from there.
Sources and more resources
- Wikipedia – Kelvin, Fahrenheit, Conversion of Units of Temperature, and Scale of Temperature – An introduction to both temperature scales and the concept of a temperature scale.
- ISO 80000-5:2019 – The ISO standard defining temperature.
- NIST Physical Measurement Laboratory – SI Units – Temperature – Details on temperature by the National Institute of Standards and Technology.
- Prof. James Schombert, Department of Physics, University of Oregon – Temperature Scale (Glossary) – An overview of the 3 common temperature scales of today, Celsius, Fahrenheit, and Kelvin.