About the k to °f calculation
Converting kelvin to fahrenheit is not a simple multiplication, because the two scales start from different zero points. One kelvin corresponds to -457.87 fahrenheit, but that ratio does not hold at other values — the formula below is what you actually need. The SI temperature unit. It starts at absolute zero, so it never goes negative and takes no degree symbol. The everyday scale in the United States, where water freezes at 32° and boils at 212°.
Formula
°F = (K − 273.15) × 9/5 + 32Worked example
Converting 300 K through the formula above gives 80.33 °F.
Frequently asked questions
How many fahrenheit are in a kelvin?
One kelvin equals -457.87 fahrenheit. Because these are temperature scales with different zero points, this is not a ratio you can multiply by — you have to apply the full formula for any other value.
How do I convert fahrenheit back to kelvin?
Reverse the formula: undo the addition first, then the multiplication. One degree Fahrenheit works out as 255.928 kelvin. Our Fahrenheit to Kelvin page does it for you.
Is this conversion exact?
Yes. The Celsius, Fahrenheit and Kelvin scales are defined in terms of each other exactly, so the conversion carries no rounding error beyond what we display.
Where is each of these units used?
Kelvin: the SI temperature unit. It starts at absolute zero, so it never goes negative and takes no degree symbol. Fahrenheit: the everyday scale in the United States, where water freezes at 32° and boils at 212°.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units