Kelvin to Fahrenheit Converter
Convert Kelvin (K) to degrees Fahrenheit (°F) instantly — or type a Fahrenheit value to convert back. Every conversion shows its work step by step, with adjustable precision, a live conversion table, and key reference temperatures.
How this conversion was calculated
Quick table around your value
| Kelvin (K) | Fahrenheit (°F) |
|---|
Reference temperatures
Kelvin to Fahrenheit conversion table
| Kelvin (K) | Fahrenheit (°F) |
|---|---|
| 0 K | -459.67 °F |
| 10 K | -441.67 °F |
| 20 K | -423.67 °F |
| 30 K | -405.67 °F |
| 40 K | -387.67 °F |
| 50 K | -369.67 °F |
| 60 K | -351.67 °F |
| 70 K | -333.67 °F |
| 80 K | -315.67 °F |
| 90 K | -297.67 °F |
| 100 K | -279.67 °F |
| 110 K | -261.67 °F |
| 120 K | -243.67 °F |
| 130 K | -225.67 °F |
| 140 K | -207.67 °F |
| 150 K | -189.67 °F |
| 160 K | -171.67 °F |
| 170 K | -153.67 °F |
| 180 K | -135.67 °F |
| 190 K | -117.67 °F |
| 200 K | -99.67 °F |
| 210 K | -81.67 °F |
| 220 K | -63.67 °F |
| 230 K | -45.67 °F |
| 240 K | -27.67 °F |
| 250 K | -9.67 °F |
| 260 K | 8.33 °F |
| 270 K | 26.33 °F |
| 280 K | 44.33 °F |
| 290 K | 62.33 °F |
| 300 K | 80.33 °F |
| 400 K | 260.33 °F |
| 500 K | 440.33 °F |
| 600 K | 620.33 °F |
| 700 K | 800.33 °F |
| 800 K | 980.33 °F |
| 900 K | 1160.33 °F |
| 1000 K | 1340.33 °F |
Kelvin to Fahrenheit formulas
Kelvin to Fahrenheit: °F = K × 9/5 − 459.67
Fahrenheit to Kelvin: K = (°F + 459.67) × 5/9
Both formulas are exact by definition. The constant 459.67 comes from the Kelvin offset: 0 °C = 273.15 K, and 273.15 × 9/5 = 491.67; subtracting the Fahrenheit freezing point of water (32 °F) gives 491.67 − 32 = 459.67. Converting through Celsius first (K → °C → °F) always gives the identical result.
Frequently asked questions
What is the formula to convert Kelvin to Fahrenheit?
The exact formula is: degrees Fahrenheit = Kelvin times 9/5, minus 459.67. Written out: F = (K x 9/5) - 459.67. For example, 300 K x 9/5 = 540, and 540 - 459.67 = 80.33. So 300 Kelvin equals 80.33 degrees Fahrenheit. The 9/5 factor comes from the ratio of the degree sizes, and 459.67 aligns the two zero points (0 K = -459.67 degrees F).
How do you convert Fahrenheit to Kelvin?
Use the inverse formula: K = (F + 459.67) x 5/9. Add 459.67 to the Fahrenheit temperature, then multiply by 5/9. For example, (32 + 459.67) x 5/9 = 491.67 x 5/9 = 273.15. So 32 degrees Fahrenheit equals 273.15 Kelvin. The calculator above does this live in both directions.
What is 0 Kelvin in Fahrenheit?
0 Kelvin equals exactly -459.67 degrees Fahrenheit. This is absolute zero, the lowest temperature physically possible, where molecular thermal motion reaches its minimum. No temperature can exist below 0 K, so -459.67 degrees F is also the coldest possible Fahrenheit reading.
What is 273.15 Kelvin in Fahrenheit?
273.15 K equals exactly 32 degrees Fahrenheit. The math: 273.15 x 9/5 = 491.67, and 491.67 - 459.67 = 32. This is the freezing (and melting) point of water at standard atmospheric pressure, and it is why the Kelvin scale is offset by 273.15 from Celsius.
What is 373.15 Kelvin in Fahrenheit?
373.15 K equals exactly 212 degrees Fahrenheit. The math: 373.15 x 9/5 = 671.67, and 671.67 - 459.67 = 212. This is the boiling point of water at sea level (1 atmosphere of pressure).
What is 100 Kelvin in Fahrenheit?
100 K equals -279.67 degrees Fahrenheit. The math: 100 x 9/5 = 180, and 180 - 459.67 = -279.67. At this temperature, gases like nitrogen and oxygen are liquids.
What is -40 degrees Fahrenheit in Kelvin?
-40 degrees Fahrenheit equals 233.15 K. The math: (-40 + 459.67) x 5/9 = 419.67 x 5/9 = 233.15. Fun fact: -40 is the one temperature where the Fahrenheit and Celsius scales read the same number (-40 F = -40 C).
Can Kelvin be negative?
No. The Kelvin scale starts at 0 K (absolute zero) and has no negative values; it measures temperature upward from the coldest physically possible point. If you enter a negative Kelvin number, this converter shows an error explaining that instead of a result, because a temperature below 0 K (below -459.67 degrees F) cannot exist.
Why does the Kelvin to Fahrenheit formula use 459.67?
The 459.67 is exact by definition, not a rounded constant. Here is the derivation: 0 degrees Celsius equals 273.15 K, and 273.15 x 9/5 = 491.67. Since 0 degrees Celsius is also 32 degrees Fahrenheit, subtracting gives 491.67 - 32 = 459.67. So F = K x 9/5 - 459.67 is algebraically identical to converting Kelvin to Celsius first and then applying F = C x 9/5 + 32.
What is the temperature of liquid nitrogen in Fahrenheit?
Liquid nitrogen boils at 77 K at atmospheric pressure, which is -321.07 degrees Fahrenheit. The math: 77 x 9/5 = 138.6, and 138.6 - 459.67 = -321.07. This extreme cold is why it is used for cryogenic freezing and preserving biological samples.
What is the Sun's surface temperature in Fahrenheit?
The Sun's visible surface (the photosphere) is about 5,778 K, which is approximately 9,940.73 degrees Fahrenheit. The math: 5,778 x 9/5 = 10,400.4, and 10,400.4 - 459.67 = 9,940.73. Astronomers use Kelvin for stellar temperatures because it starts at absolute zero.
What is normal human body temperature in Kelvin?
98.6 degrees Fahrenheit equals 310.15 K. The math: (98.6 + 459.67) x 5/9 = 558.27 x 5/9 = 310.15. A comfortable room temperature of 68 degrees F is 293.15 K, and water freezes at 32 degrees F, which is 273.15 K.
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