Convert Celsius to Kelvin instantly
Type any temperature in Celsius and this calculator gives you the Kelvin value straight away — no formula to remember, no arithmetic to check. It works for everything from everyday weather to chemistry homework to scientific lab reports.
0 °C = 273.15 K — that is the single most-searched conversion on this page, and the answer you will find confirmed below.
Quick Celsius to Kelvin reference table
These are exact values using the standard conversion formula. Use this table to check your work or grab a common value at a glance.
| Celsius (°C) | Kelvin (K) |
|---|---|
| 1 °C | 274.15 K |
| 2 °C | 275.15 K |
| 5 °C | 278.15 K |
| 10 °C | 283.15 K |
| 25 °C | 298.15 K |
| 50 °C | 323.15 K |
| 100 °C | 373.15 K |
The conversion factor is always +273.15. To go the other way (Kelvin to Celsius), subtract 273.15.
How to use this converter
- Find the converter above this page.
- Make sure Celsius is selected as the "from" unit and Kelvin as the "to" unit.
- Type your temperature into the input box.
- The Kelvin result appears immediately — no button to press.
- Need the reverse? Switch the units to go from Kelvin back to Celsius.
Worked example: converting 37 °C to Kelvin
Normal human body temperature is 37 °C. Here is the step-by-step conversion:
- Start with the temperature: 37 °C
- Add 273.15 to it: 37 + 273.15 = 310.15 K
So 37 °C = 310.15 K. You will see exactly this in a medical or biology textbook.
How the Celsius to Kelvin formula works
Kelvin is the SI unit (the international standard unit) for temperature. It starts at absolute zero — the coldest temperature physically possible — so it never goes negative. Celsius is offset from Kelvin by exactly 273.15 degrees.
The formula is simply:
K = °C + 273.15That is all there is to it. The scale size is identical — a 1-degree change in Celsius equals a 1-degree change in Kelvin. Only the starting point differs.
For the reverse (Kelvin to Celsius):
°C = K - 273.15Common ways people phrase this conversion
All of these mean exactly the same thing — they all use K = °C + 273.15:
- "Convert °C to K" — the shorthand form used in science classes.
- "Change Celsius to Kelvin" — common in chemistry problems.
- "Temperature in Kelvin from Celsius" — you might see this in physics or thermodynamics.
- "Absolute temperature from Celsius" — Kelvin is sometimes called the absolute temperature scale.
If someone asks you to convert to Kelvin from Fahrenheit, that is a two-step process: convert Fahrenheit to Celsius first, then add 273.15. The converter above handles that too — just change the "from" unit.
Quick tips and common mistakes
- Never write a degree symbol with Kelvin. It is always written as 273 K, not 273 °K. This is a very common error in homework and lab reports.
- Kelvin is never negative. If your answer comes out below zero, you have subtracted instead of added — flip the sign.
- Absolute zero is 0 K = −273.15 °C. Nothing can be colder than this.
- Water freezes at 273.15 K (0 °C) and boils at 373.15 K (100 °C) — useful sanity-check values.
- If you only need a rough answer, rounding to +273 is fine for everyday estimates, but use 273.15 for science work.
Everything on this page is calculated entirely in your browser — no data is sent anywhere. Your temperature values stay private.
Use the converter at the top of this page to convert any Celsius temperature to Kelvin in one second.