Kelvin to Celsius Converter

Change kelvin to degrees Celsius as you type, with the working shown, why kelvin has no degree sign, a chart of the kelvin values people look up most and the 273 or 273.15 question explained. Type in the Celsius box to go the other way.

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Last updated: 9 November 2026

Convert Kelvin to Celsius

Kelvin (K)

Celsius (°C)

300 K = 26.85 °C

How 300 K becomes 26.85 °C

Step 1: − 273.15300 − 273.15 = 26.85 °C
Same size degrees1 K change = 1 °C change
School shortcut300 − 273 = 27 °C

Updates as you type. Type in either box. Need the other way? Celsius to Kelvin

Round to

Nothing can be colder than absolute zero: 0 K or −273.15 °C. Values below it are not accepted.

Quick Conversions

Kelvin to Celsius Formula

°C = K − 273.15

Subtract 273.15 from the kelvin number
Example: 300 K − 273.15 = 26.85 °C
Kelvin has no degree sign: write 300 K, not 300 °K
0 K is absolute zero, which is −273.15 °C

273 or 273.15?

School problems often subtract 273. The exact value is 273.15, so the answer is a little different.

Kelvin	Exact (− 273.15)	School (− 273)
0 K	−273.15 °C	−273 °C
100 K	−173.15 °C	−173 °C
273.15 K	0 °C	0.15 °C
300 K	26.85 °C	27 °C
373.15 K	100 °C	100.15 °C

Use 273.15 when you need the exact answer, and 273 only when your teacher or book says to.

Kelvin to Celsius Chart

From absolute zero to 1,000 K. Click a row to convert it.

Kelvin	Celsius
	−273.15 °C
	−272.15 °C
	−263.15 °C
	−248.15 °C
	−223.15 °C
	−173.15 °C
	−73.15 °C
	−23.15 °C
	0 °C
	0.01 °C
	20 °C
	25 °C
	26.85 °C
	37 °C
	100 °C
	226.85 °C
	726.85 °C

°C = K − 273.15. Use Print to print this page with the chart.

Popular Kelvin Values

Kelvin values people look up, and the usual reference points. Click one to use it.

Kelvin	Celsius
	−248.15 °C
	−273.15 °C
	0 °C
	20 °C
	25 °C
	26.85 °C
	37 °C
	100 °C

25 K and 0 K are the most searched values. 273.15 K is 0 °C, and 373.15 K is 100 °C.

Kelvin Has No Degree Sign

People search for degrees kelvin, but the unit is simply the kelvin.

Write	Not
300 K	300 °K
kelvin	degrees kelvin
26.85 °C	26.85 K (that would be a different temperature)

Celsius keeps the degree sign: 26.85 °C. Kelvin is written with just the letter K.

Key Temperatures

The reference points, in kelvin, Celsius and Fahrenheit.

Point	K	°C	°F
Absolute zero	0	−273.15	−459.67
Triple point of water	273.16	0.01	32.02
Water freezes	273.15	0	32
Body temperature (typical)	310.15	37	98.6
Water boils (about, sea level)	373.15	100	212

Water boils at about 100 °C only at standard sea-level pressure.

Kelvin vs Celsius

The two scales use the same size of degree.

	Kelvin	Celsius
Symbol	K (no degree sign)	°C
Water freezes	273.15 K	0 °C
Steps freezing to boiling	100	100
Lowest possible	0 K	−273.15 °C
Negative values	None	Yes

A change of 1 K is exactly a change of 1 °C, so temperature differences are the same in both.

Other Temperature Scales

Temperature Converter, all four scales: Celsius, Fahrenheit, kelvin and Rankine, with all 12 formulas.
Celsius to Kelvin, the same page the other way.
Celsius to Fahrenheit, the same page for °F.
Fahrenheit to Kelvin, °F to kelvin.
Kelvin to Fahrenheit, kelvin to °F.

About Kelvin to Celsius Conversion

Type a kelvin temperature and the Celsius answer appears as you type, with the working. Use it for chemistry, physics, school and science. Your numbers never leave your browser. Use it for everyday sums, not as a laboratory instrument.

Use this free Kelvin to Celsius converter to change a temperature from kelvin to degrees Celsius. Type a number in the Kelvin box and the Celsius answer appears as you type, with the working shown. You can also type in the Celsius box to go the other way. Pick how many decimals to round to and copy a link to your conversion. Tables list a chart from absolute zero to 1,000 K, popular kelvin values, how to write kelvin without a degree sign, key temperatures such as absolute zero and the triple point of water, and the difference between 273 and 273.15. It is free and instant, and your numbers stay in your browser.

How to convert Kelvin to Celsius

Kelvin and Celsius use the same size of degree, so you only subtract a fixed number. To change kelvin to Celsius, subtract 273.15.

°C = K − 273.15

For 300 K: 300 − 273.15 = 26.85 °C. For 273.15 K, the freezing point of water: 273.15 − 273.15 = 0 °C. For 373.15 K, the boiling point at sea level: 373.15 − 273.15 = 100 °C. To go back, add 273.15: K = °C + 273.15.

Why kelvin has no degree sign

Kelvin is the SI unit of temperature, so it is written with just the letter K: 300 K, not 300 °K. It used to be called "degree Kelvin", and many people still say degrees kelvin, but the unit is simply the kelvin. Celsius keeps the degree sign: 26.85 °C.

Should you add 273 or 273.15?

The exact value is 273.15. School problems often use 273 to keep the sums short, which makes the answer 0.15 °C higher: 300 K is 26.85 °C exactly, and 27 °C with the school shortcut. Use 273.15 when you need the exact answer and 273 only when your teacher or book says to.

Common conversions

0 K is −273.15 °C, 25 K is −248.15 °C, 273.15 K is 0 °C, 293.15 K is 20 °C, 298.15 K is 25 °C, 300 K is 26.85 °C, 310.15 K is 37 °C and 373.15 K is 100 °C. The chart above lists more, from absolute zero to 1,000 K, and the table of popular values shows the ones people look up most.

Absolute zero and the triple point of water

Absolute zero is the lowest temperature possible: 0 K, which is −273.15 °C. Kelvin starts there, so it has no negative values. The triple point of water, where ice, liquid water and vapour exist together, is 273.16 K, which is 0.01 °C.

Same size degrees

A change of 1 K is exactly a change of 1 °C. If a temperature rises by 10 K it rises by 10 °C, so temperature differences are the same in both scales. Only the starting point is different, and that is why you subtract 273.15.

Celsius to Kelvin

To go the other way, add 273.15: 25 °C is 25 + 273.15 = 298.15 K. You can do it here by typing in the Celsius box, or use the Celsius to Kelvin converter, which has its own chart. For Celsius to Fahrenheit, use the Celsius to Fahrenheit converter, and for all four scales use the Temperature Converter.

Spelling

The correct spellings are kelvin and Celsius. Many people type "kalvin" or "celcius", and this page is for them too.

View All Converters

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Frequently Asked Questions

How do I convert Kelvin to Celsius?

Subtract 273.15 from the kelvin temperature. For example, 300 K − 273.15 = 26.85 °C, and 273.15 K is 0 °C.

What is the formula for Kelvin to Celsius?

°C = K − 273.15. To go the other way, K = °C + 273.15. A kelvin and a degree Celsius are the same size, so you only add or subtract the fixed number.

What is 300 K in Celsius?

26.85 °C. The sum is 300 − 273.15 = 26.85.

What is 0 K in Celsius?

−273.15 °C. 0 K is absolute zero, the lowest temperature possible.

What is 273.15 K in Celsius?

0 °C, the freezing point of water. The sum is 273.15 − 273.15 = 0.

What is 25 K in Celsius?

−248.15 °C. The sum is 25 − 273.15 = −248.15. It is a very cold temperature, close to absolute zero.

What is 298.15 K in Celsius?

25 °C. The sum is 298.15 − 273.15 = 25.

What is 373.15 K in Celsius?

100 °C, the boiling point of water at standard sea-level pressure. The sum is 373.15 − 273.15 = 100.

Do I subtract 273 or 273.15?

The exact value is 273.15. School problems often use 273, which makes the answer 0.15 °C higher: 300 K is 26.85 °C exactly and 27 °C with the shortcut. Use 273 only when your teacher or book says to.

Why does kelvin have no degree sign?

Kelvin is the SI unit of temperature, so it is written with just the letter K, such as 300 K. It used to be called degree Kelvin, and many people still say degrees kelvin, but the unit is simply the kelvin.

Can kelvin be negative?

No. Kelvin starts at absolute zero, 0 K, the lowest temperature possible, so it has no negative values. Celsius can be negative, down to −273.15 °C.

What is absolute zero in Kelvin and Celsius?

0 K, which is −273.15 °C. Nothing can be colder, so the converter does not accept a lower value.

Is a change of 1 K the same as a change of 1 °C?

Yes. The two scales use the same size of degree, so a rise of 10 K is a rise of 10 °C. Only the starting points differ, which is why you subtract 273.15.

Is it kelvin or kalvin? And Celsius or Celcius?

The correct spellings are kelvin and Celsius. Many people type kalvin or celcius, and this converter is for them too.

Can I convert Celsius to Kelvin here?

Yes. Type the number in the Celsius box and the Kelvin box shows the answer. For 25 °C the sum is 25 + 273.15 = 298.15 K. There is also a page just for Celsius to Kelvin.

Are my numbers saved or shared?

No. The conversion happens in your browser, and the numbers you type are not stored or sent to any server. A link you copy keeps the numbers after the # sign, which browsers never send to a server.