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Celsius → Kelvin | Converter
Convert Celsius to Kelvin with the formula below. 1 °C ≈ 274.15 K
Quick Insight
1 Celsius = 274.15 Kelvin
20 °C ≈ 293.15 K; -10 °C ≈ 263.15 K. A rise of 5 °C is a rise of 5 K. Do not add 273.15 to a temperature difference.
💡 Tip: Add exactly 273.15 to the Celsius reading. There is no multiplication by 1.8 in this conversion.
Classroom tables and temperature data
Mathematical Facts
🌡️Conversion formula: K = °C + 273.15
Convert Celsius to Kelvin with the formula below. K = °C + 273.15. These formulas convert temperature readings, not temperature differences. Temperature scales have different zero points. Use this direction to put Celsius readings into a classroom table or data field that requires kelvins. The size of the unit stays the same; only the zero point shifts by 273.15.
Why This Conversion Matters
Celsius and kelvin have equal-sized intervals, but a reading of 20 °C is not a reading of 20 K. Applying the fixed offset lets both columns describe the same temperature. 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
Classroom tables and temperature data
A practice table can include a 20 °C reading and a −10 °C reading. Adding the same offset to each preserves the temperature difference between the rows.
Examples:
- 20 °C ≈ 293.15 K
- -10 °C ≈ 263.15 K
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
Using 273 as though it were the exact offset
At 20 °C this gives 293 K rather than 293.15 K. It is a shortcut that is 0.15 K low, not the exact relation.
✓ Add exactly 273.15 to the Celsius reading. There is no multiplication by 1.8 in this conversion.
Putting a temperature change into a converter for temperature readings
A rise of 5 °C is a rise of 5 K. Do not add 273.15 to 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
- ✓Add exactly 273.15 to the Celsius reading. There is no multiplication by 1.8 in this conversion.
- ✓A rise of 5 °C is a rise of 5 K. Do not add 273.15 to a temperature difference.
- ✓Write the result with K, without a degree sign. Preserve any minus sign in the Celsius input before adding the offset.
Frequently Asked Questions
How do I calculate the conversion?
K = °C + 273.15. These formulas convert temperature readings, not temperature differences. Temperature scales have different zero points.
What is an example?
0 °C ≈ 273.15 K; 20 °C ≈ 293.15 K; 100 °C ≈ 373.15 K
Does this formula also convert a temperature rise or fall?
A rise of 5 °C is a rise of 5 K. Do not add 273.15 to a temperature difference. For a rise, fall or difference, use only the interval relationship. Do not apply the zero-point offsets to the difference.
Do Celsius and kelvin have the same size unit?
Yes. A change of one degree Celsius has the same size as a change of one kelvin. Their temperature readings differ by 273.15, so equal interval size does not mean equal readings.
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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