Kelvin to Celsius Converter
Convert Kelvin (K) to Celsius (°C) instantly, or use the conversion table below to look up common values.
Kelvin to Celsius conversion table
| Kelvin (K) | Celsius (°C) |
|---|---|
| 1 | -272.15 |
| 2 | -271.15 |
| 3 | -270.15 |
| 4 | -269.15 |
| 5 | -268.15 |
| 10 | -263.15 |
| 25 | -248.15 |
| 50 | -223.15 |
| 100 | -173.15 |
How to convert Kelvin to Celsius
1 K equals -272.15 °C. Use the converter above for any value, or read the table for common conversions.
°C = K − 273.15 · K = °C + 273.15Temperature is an offset scale rather than a simple multiplier, so use the formulas above — multiplying a Celsius figure by 9/5 without adding 32 gives the wrong answer.
Worked examples
- 0 K= -273.15 °C
- 10 K= -263.15 °C
- 20 K= -253.15 °C
- 37 K= -236.15 °C
- 100 K= -173.15 °C
What these units are
Kelvin (K). Kelvin is the SI base unit of temperature. It starts at absolute zero, the coldest temperature possible, and uses the same degree size as Celsius — so 0 °C is 273.15 K.
Celsius (°C). Celsius is the metric temperature scale: 0 °C is the freezing point of water and 100 °C its boiling point at sea level. It is the everyday scale in Tanzania and most of the world.
The arithmetic is exact; only the display is rounded. 37 °C is exactly 98.6 °F, while 36.6 °C displays as 97.9 °F.
Converting Kelvin to Celsius in practice
Working in kelvin
Kelvin is the SI base unit of temperature. It begins at absolute zero, the coldest temperature possible, and its degree size is identical to the Celsius degree, so 0 °C is 273.15 K exactly.
Kelvin is used in science and engineering, especially thermodynamics, astronomy, cryogenics and gas calculations, where temperatures must be measured from absolute zero rather than from a water reference point.
Kelvin shares the Celsius degree size, so a temperature difference of one kelvin equals a difference of one degree Celsius. The scales differ only by the offset of 273.15.
A common error is writing a Celsius value with the kelvin symbol; 25 °C is 298.15 K, and 25 K is far colder. Kelvin is written without a degree symbol, and ordinary temperatures are never negative on this scale.
Kelvin is the outlier in its dimension because its zero is absolute zero, while Celsius and Fahrenheit place their zeros at chosen reference points. Weather, cooking and body temperature use those two, and laboratory work uses Kelvin.
Reading the result in celsius
Celsius is an affine temperature scale with two fixed points: water freezes at 0 °C and boils at 100 °C at one atmosphere. It is not a multiplier applied to a quantity.
Celsius is the everyday scale for weather reporting, cooking and oven settings, refrigeration, medicine and most laboratory and engineering work, and it is the working scale wherever metric measures are used.
Celsius is an offset scale, so a Fahrenheit value cannot be converted by multiplying by 1.8 alone; 32 must be added or subtracted. Absolute zero is −273.15 °C, which is 0 K.
A common error is quoting a body temperature in Fahrenheit without noting that this site is Celsius-first, so 98.6 °F appears as 37 °C here. The two scales meet only at −40.
Celsius and Fahrenheit share the weather, oven and body-temperature roles, so a bare number is ambiguous; 30 means a hot day in Celsius and a cold one in Fahrenheit. Kelvin takes over in scientific work where absolute values matter.
Checking a kelvin to celsius conversion
Celsius to Kelvin is the only temperature pair that behaves like a simple conversion: same degree size, different zero, so the value shifts by 273.15 and no multiplication is involved. Every pair involving Fahrenheit is affine, meaning a scale factor and an offset applied together.
That is why this dimension is the exception to the rest of the converter. Multiplying a Celsius figure by 9/5 gives a number that is not a Fahrenheit temperature, because the 32-degree offset is still missing. The result only becomes correct when the addition is made in the right order.
Checking a temperature conversion is easiest at a value whose answer you know: water freezing and boiling, body temperature, or the single reading of −40 where the Celsius and Fahrenheit scales agree. The error to watch for is dropping the offset when converting a temperature difference, where it genuinely does not apply.
Tanzania reference points
Real quantities, converted into the units on this page.
Tanzania's long-term mean monthly maximum temperature
28.2 °C = 301.35 K
The 1981–2010 baseline is 28.2 °C against 28.5 °C for 2012–2018, which the report reads as a warming trend. It is a national mean across meteorological stations, not the temperature in any one town.
Source: National Bureau of Statistics — National Climate Change Report 2019 (Tanzania Meteorological Agency station data) · verified 2026-09-14
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