Celsius to Kelvin Converter – K = °C + 273.15
Same degree size, different zero — convert °C to K
Direction locked to °C → K
Formula & steps
K = °C + 273.15
K = °C + 273.15 K = 25 + 273.15 K = 298.15
Common values
Engineering examples
These values are common engineering examples (datasheet corners, room temperature, and high-temperature ratings). They are not a universal operating-temperature rating for every electronic component.
Natural-language input accepted: 25C, -40 F, 300K.
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Quick Answer
K = °C + 273.15. 0°C = 273.15 K, 25°C = 298.15 K, 100°C = 373.15 K. Kelvin never uses a degree symbol.
Celsius to Kelvin Converter
K = °C + 273.15. There is no 9/5 factor — Celsius and Kelvin share the same degree size. Only the zero point moves.
Formula and steps
- Start from the Celsius reading.
- Add 273.15.
- Write the result as K, not °K.
Example: 25°C → 25 + 273.15 = 298.15 K (the usual electronics datasheet reference).
Celsius to Kelvin chart
| °C | K | Typical mention |
|---|---|---|
| −273.15 | 0 | Absolute zero |
| −40 | 233.15 | Industrial / automotive corner |
| 0 | 273.15 | Water freeze |
| 20 | 293.15 | Indoor air example |
| 25 | 298.15 | Datasheet reference |
| 70 | 343.15 | Commercial high |
| 85 | 358.15 | Industrial high |
| 125 | 398.15 | Automotive junction example |
| 100 | 373.15 | Water boil |
Electronics noise and thermal-voltage calculations use kelvin because they start from absolute zero. Operating ranges on the same datasheet are still written in °C.
Related
- Reverse: Kelvin to Celsius
- Temperature Converter
- Junction Temperature Calculator
- Temperature Difference Calculator — 1°C of rise = 1 K of rise
Design Notes
Electronics datasheets use Celsius exclusively. Standard operating ranges: commercial (0-70°C), industrial (-40 to 85°C), automotive (-40 to 125°C). Junction temperature is the most critical thermal parameter for IC reliability. Common corner values such as -55°C or 125°C are examples, not a universal rating for every part.
Common Mistakes
- 1
Forgetting the offset in Celsius-Fahrenheit conversion — it is NOT a simple multiplication.
- 2
Using ° symbol with Kelvin — correct notation is simply K, not °K.
- 3
Confusing temperature difference with absolute temperature — a 10°C rise = 18°F rise, but 10°C = 50°F.
Engineering Handbox
K = °C + 273.15 K = 25 + 273.15 = 298.15
Knowledge Base
How do I convert Celsius to Kelvin?
Add 273.15. The size of one degree is the same on both scales.
Why do datasheets use 298.15 K?
298.15 K is 25°C, the usual electrical characterization temperature. This page only converts the number.