Kelvin to Celsius

Convert kelvin to celsius instantly, right here.

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Use Kelvin to Celsius

Converts kelvin to celsius in this tab, with nothing sent anywhere.

Kelvin

Runs entirely on your deviceThe conversion happens in this browser tab. Nothing you type is uploaded, logged or stored, which is worth knowing for anything you would not paste into a search box.

Celsius

Type or paste, then run.

The result will appear here.

A thermodynamic reading of 300 K equals 26.85 °C. Do not use this conversion for a lamp advertised as 3000 K: colour temperature describes the appearance of its light, not the physical temperature of the room or bulb.

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About Kelvin to Celsius

Kelvin readings come out of scientific instruments, colour-temperature specs and physics problems, but to picture them as everyday warmth you want Celsius. Converting Kelvin to Celsius simply subtracts 273.15. A star's 5778 K surface, a 300 K room, a 4000 K warm-white bulb each become a Celsius figure you can reason about - 300 K, for instance, is a comfortable 26.85 °C. Lighting is a everyday case: a bulb rated 2700 K sounds abstract until you see it is a warm indoor temperature far below a daylight-balanced 6500 K one. Photography white balance is set in Kelvin, and converting to Celsius makes it concrete: a 3200 K tungsten lamp is far cooler in real warmth than the number suggests. A change of one kelvin is a change of one Celsius degree, even though the two scales have different zero points. For example, 300 K is 26.85 Celsius. Kelvin symbols do not take a degree sign, unlike Celsius and Fahrenheit notation.

Using Kelvin to Celsius

Type a number of degrees. You can paste a value with its unit; the tool reads the number.
The exact factor is applied and the result is shown as °C, updating live as you type.
Copy the answer, or switch to the reverse converter to go from °C back to K.

Where kelvin to celsius helps

A colour temperature

A 300 K reading is about 26.85 °C, a warm room.

Both directions

Need the opposite? The °C-to-K converter is linked below and uses the exact inverse factor.

A Kelvin value is an absolute reading

Subtract 273.15 to convert a reading: 300 K is 26.85 C. A change from 300 K to 310 K is a rise of 10 K and also 10 C, so do not subtract 273.15 from the difference itself. Check that the original quantity really is a temperature rather than a colour-temperature label describing the appearance of a light source.

Before you use the result

The result is rounded for readability, so a value converted and then converted back may differ in the last decimal place. The underlying factor is exact.
Units in your input are ignored - only the number is read - so make sure the figure you type is really in K.

Questions about Kelvin to Celsius

Can Kelvin be negative?

No - Kelvin starts at absolute zero, so it is never negative. Subtracting 273.15 to reach Celsius, though, often gives a negative everyday temperature.

Is my data uploaded?

No. Kelvin to Celsius does the arithmetic in this browser tab; the value is calculated on your device and is not sent to a server.