Celsius to Kelvin Converter
Convert Celsius to kelvin — add 273.15. The degree is the same size; only the zero point moves. Results update as you type; exact factors shown.
One degree Celsius is 274.15 kelvins — see the exact factor, not a rounded rule of thumb.
How the celsius to kelvin converter works
Celsius and Fahrenheit are offset scales, so the conversion is not a simple multiplication: °F = °C × 9/5 + 32 and °C = (°F − 32) × 5/9. Kelvin has the same size of degree as Celsius but starts at absolute zero: K = °C + 273.15. The two scales meet at −40°.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common temperature conversions
| From | To | Units |
|---|---|---|
| -273.15 °C | 0 K | degrees Celsius to kelvins |
| -100 °C | 173.15 K | degrees Celsius to kelvins |
| -40 °C | 233.15 K | degrees Celsius to kelvins |
| 0 °C | 273.15 K | degrees Celsius to kelvins |
| 20 °C | 293.15 K | degrees Celsius to kelvins |
| 25 °C | 298.15 K | degrees Celsius to kelvins |
| 37 °C | 310.15 K | degrees Celsius to kelvins |
| 100 °C | 373.15 K | degrees Celsius to kelvins |
| 200 °C | 473.15 K | degrees Celsius to kelvins |
| 500 °C | 773.15 K | degrees Celsius to kelvins |
| 1,000 °C | 1,273.15 K | degrees Celsius to kelvins |
| 1,500 °C | 1,773.15 K | degrees Celsius to kelvins |
Units in this converter and their exact factors
| Unit | Symbol | To kelvin |
|---|---|---|
| degree Celsius | °C | x+273.15 |
| degree Fahrenheit | °F | (x-32)×5÷9+273.15 |
| kelvin | K | x |
FAQFrequently asked questions about temperature conversion
What is the formula?
K = °C + 273.15. There is no multiplication because a kelvin and a Celsius degree are exactly the same size.
What is absolute zero?
0 K, which is −273.15°C — the point where thermal motion is at its minimum.
Why is there no degree sign?
Kelvin is an absolute scale, so the SI convention is "300 K", not "300°K".
What is room temperature in kelvin?
About 293 K for 20°C.
Why do scientists use kelvin?
Because gas laws and thermodynamics need a scale that starts at true zero — doubling the kelvin temperature doubles the thermal energy, which is not true in Celsius.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.