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Kelvin → Celsius | Converter
Convert Kelvin to Celsius with the formula below. 1 K ≈ -272.15 °C
Quick Insight
1 Kelvin = -272.15 Celsius
293.15 K ≈ 20 °C; 300 K ≈ 26.85 °C. A rise of 5 K is a rise of 5 °C. Do not subtract 273.15 from a temperature difference.
💡 Tip: Subtract exactly 273.15 from the kelvin reading. Do not multiply by 5/9 or 9/5.
Reading kelvin tables in Celsius
Mathematical Facts
🌡️Conversion formula: °C = K - 273.15
Convert Kelvin to Celsius with the formula below. °C = K - 273.15. These formulas convert temperature readings, not temperature differences. Temperature scales have different zero points. Use this direction to read a kelvin value from an educational table or dataset on a Celsius display. Subtract the scale offset; the size of the temperature interval does not change.
Why This Conversion Matters
The result describes the same temperature with a different zero point. A positive kelvin reading can become a negative Celsius reading, so retain the sign of the result. The calculator uses the full stored factor and rounds displayed results to 12 significant digits. Display precision is not a guarantee of measurement accuracy.
Real-World Examples
Reading kelvin tables in Celsius
Compare example data values of 293.15 K and 300 K with a Celsius display. Convert each reading separately and keep the original kelvin column for reference.
Examples:
- 293.15 K ≈ 20 °C
- 300 K ≈ 26.85 °C
Pro Tips:
- ✓Keep the original reading and unit beside the converted value. Calculate first, then round to a precision useful for the display or comparison.
History & Background
In 1967 the CGPM adopted the name kelvin and symbol K in place of degree kelvin and °K. The current definition was adopted in 2018 and fixes the numerical value of the Boltzmann constant.
Common Mistakes to Avoid
Subtracting 273 as though it were exact
At 300 K this gives 27 °C rather than 26.85 °C. That shortcut is 0.15 °C high.
✓ Subtract exactly 273.15 from the kelvin reading. Do not multiply by 5/9 or 9/5.
Putting a temperature change into a converter for temperature readings
A rise of 5 K is a rise of 5 °C. Do not subtract 273.15 from a temperature difference.
✓ For a rise, fall or difference, use only the interval relationship. Do not apply the zero-point offsets to the difference.
Pro Tips
- ✓Subtract exactly 273.15 from the kelvin reading. Do not multiply by 5/9 or 9/5.
- ✓A rise of 5 K is a rise of 5 °C. Do not subtract 273.15 from a temperature difference.
- ✓A negative Celsius result is not by itself a conversion error: 263.15 K is −10 °C. Check the unit as well as the sign.
Frequently Asked Questions
How do I calculate the conversion?
°C = K - 273.15. These formulas convert temperature readings, not temperature differences. Temperature scales have different zero points.
What is an example?
0 K ≈ -273.15 °C; 20 K ≈ -253.15 °C; 100 K ≈ -173.15 °C
Does this formula also convert a temperature rise or fall?
A rise of 5 K is a rise of 5 °C. Do not subtract 273.15 from a temperature difference. For a rise, fall or difference, use only the interval relationship. Do not apply the zero-point offsets to the difference.
Why can a positive kelvin value give a negative Celsius result?
Celsius zero is 273.15 K. A kelvin reading below 273.15 K therefore becomes negative after subtracting the offset; for example, 263.15 K is −10 °C.
Do extra decimal places make the original measurement more accurate?
No. The conversion changes the scale, not the measurement. Keep any uncertainty and the original display resolution in mind; a longer decimal result does not add information to the reading.
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