CalcOpenly
English

Kelvins to degrees Fahrenheit converter

Convert kelvins to degrees Fahrenheit (Kelvin to Fahrenheit) with the exact formula, a conversion chart and worked steps.

Drafted with AI writing toolsUpdated Checked examples: 3

K
Try
Degrees Fahrenheit
°F
Degrees Fahrenheit: 80.33 °F
Significant figures: 12; Nearest, ties away from zero
Conversion
300 K = 80.33 °F

300 K is about 80.33 °F.

Kelvins to degrees Fahrenheit

-400-20002000100200300K°F300 → 80.33
Kelvin to Fahrenheit chart Rows: 5
KelvinsDegrees Fahrenheit
0−459.67
255.372−0.0004
273.1532
30080.33
373.15212
How it's calculated S

  1. Apply the formula

    ∘F=K×95−459.67⇒300 K=80.33 °F{}^\circ F = K \times \tfrac{9}{5} - 459.67\quad\Rightarrow\quad 300\ \text{K} = 80.33\ \text{°F}

About the kelvins to degrees Fahrenheit converter

Kelvin is an absolute temperature scale used in physical equations. Its zero is absolute zero, and the unit is written K without a degree symbol. Restating a laboratory temperature on an everyday scale changes the numerical zero point without changing the physical temperature.

kelvin → degree Fahrenheit uses a formula because the temperature scales start at different zero points. For example, 300 K is about 80.33 °F.

The Celsius and kelvin scales have the same step size; a Fahrenheit degree is 5/9 of a Celsius degree. Absolute zero is 0 K, −273.15 °C or −459.67 °F, and inputs below it are rejected.

How to convert Kelvin to Fahrenheit

Multiply the kelvin value by 1.8 (which is 9/5), then subtract 459.67: °F = K × 1.8 − 459.67. So 300 K is 540 − 459.67 = 80.33 °F, 273.15 K is 32 °F and 373.15 K is 212 °F. Use it to report a lab or physics result on the US scale.

Why multiply by 1.8, then subtract 459.67

A kelvin is 1.8 times as large as a Fahrenheit degree, and absolute zero, 0 K, sits at −459.67 °F. Multiplying first changes the degree size; subtracting then moves the zero point to where Fahrenheit puts it.

Going through Celsius gives the same answer: (300 − 273.15) × 1.8 + 32 = 80.33 °F (NIST).

Kelvin to Fahrenheit chart

KelvinsDegrees Fahrenheit
0-459.67
200-99.67
273.1532
293.1568
30080.33
373.15212

Worked examples

  • Liquid nitrogen, about 77 K: 77 × 1.8 = 138.6, and 138.6 − 459.67 = −321.07 °F.
  • Chemistry reference temperature, 298.15 K: 298.15 × 1.8 = 536.67, and 536.67 − 459.67 = 77 °F.
  • The Sun's surface, about 5,772 K: 5,772 × 1.8 = 10,389.6, and 10,389.6 − 459.67 = 9,929.93 °F.

Keep the decimals near 0 °F

0 °F is 255.372222… K, a repeating decimal, so a rounded kelvin value lands slightly off zero. 255.372 K is −0.0004 °F, and 255.37 K is −0.004 °F. Report only as many decimals as the original reading had.

Differences and uncertainties: multiply by 1.8 only

A change of temperature has no zero to move. A 5 K rise is a 5 × 1.8 = 9 °F rise, and an uncertainty of ±0.5 K is ±0.9 °F.

Running the 5 K rise through the full formula would give −450.67 °F, a reading near absolute zero, not a change.

Common mistakes

  • Subtracting before multiplying. (300 − 459.67) × 1.8 = −287.41 °F, far from the true 80.33 °F. Multiply first.
  • Rounding 459.67 to 460. 300 K becomes 80 °F instead of 80.33 °F.
  • Using 5/9. That ratio belongs to the Fahrenheit-to-kelvin direction; 300 × 5/9 − 459.67 gives −293.00 °F.
  • A negative kelvin value. Nothing is colder than 0 K (−459.67 °F), so a negative kelvin value means the source used another scale.

The Fahrenheit to Kelvin converter reverses the formula, Kelvin to Celsius needs only a subtraction, and the temperature converter covers Rankine and Réaumur.

Worked examples

300 K to °F

Kelvins (K)
300 K
Degrees Fahrenheit
80.33 °F

Checked against: Exact-fraction computation from the legal unit definitions

255.372 K to °F

Kelvins (K)
255.372 K
Degrees Fahrenheit
-0.0004 °F

Checked against: Exact-fraction computation from the legal unit definitions

0 K to °F

Kelvins (K)
0 K
Degrees Fahrenheit
-459.67 °F

Checked against: Exact-fraction computation from the legal unit definitions

Questions

What is the formula to convert kelvin → degree Fahrenheit?

Use °F = K × 9/5 − 459.67. For example, 300 K × 1.8 − 459.67 = 80.33 °F.

About this calculator

∘F=K×95−459.67{}^\circ F = K \times \tfrac{9}{5} - 459.67

Sources

  1. NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B
  2. NIST Handbook 44, Appendix C: General tables of units of measurement
  3. BIPM, The International System of Units (SI Brochure), 9th edition

Checked against references

This calculator includes 3 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.

Put this calculator on your site

Paste this where you want the calculator to appear. It is free to use, it stays in step with corrections made here, and the credit line below it links back so your readers can find the full version.

Height
Preview the embed

Keep the credit line. It is the only condition, and it is what keeps these calculators free.

Related calculators