Celsius to Kelvin Converter (°C to K)

Celsius to Kelvin

Degrees Celsius (°C) to kelvins (K).

Value

Convert to

298.15K

Precision (significant figures)

Formula

K = °C + 273.15

1 °C = 274.15 K

Degrees Celsius (°C)	Kelvins (K)
−273.15	0
−200	73.15
−100	173.15
−40	233.15
0	273.15
20	293.15
25	298.15
37	310.15
100	373.15
200	473.15
300	573.15
500	773.15
1,000	1,273.15
1,500	1,773.15
2,000	2,273.15
5,000	5,273.15

Degrees Celsius (°C)

Kelvins (K)

−273.15

−200

73.15

−100

173.15

−40

233.15

273.15

293.15

298.15

310.15

100

373.15

200

473.15

300

573.15

500

773.15

1,000

1,273.15

1,500

1,773.15

2,000

2,273.15

5,000

5,273.15

When you need this conversion

Physics and chemistry (gas laws and thermodynamics need absolute temperatures), color temperature for lighting and photography, cryogenics, and astronomy.

Reference points

−273.15 °C = 0 K (absolute zero)
−196 °C = 77.15 K (liquid nitrogen boils)
0 °C = 273.15 K
25 °C = 298.15 K (standard lab temperature)
100 °C = 373.15 K

Why absolute temperature matters

Formulas like the ideal gas law (PV = nRT) only work with absolute temperatures. Doubling from 10 °C to 20 °C isn’t doubling the heat energy: in kelvin it’s 283.15 K to 293.15 K, a rise of about 3.5%.

Color temperature

Lighting is rated in kelvin: 2700 K is warm white, 4000 K is neutral and 6500 K is daylight. These aren’t converted to Celsius in practice, but the scale is the same.

Common mistakes

Adding 273 instead of 273.15. Close for most uses, but exact work needs the .15.

Writing °K. The unit is K, with no degree sign.

For the reverse, use kelvin to Celsius.

Questions

What is 0 °C in kelvin?

273.15 K.

What is room temperature in kelvin?

About 293–298 K (20–25 °C). Chemistry often uses 298.15 K (25 °C) as standard conditions.

Why is there no degree symbol for kelvin?

The kelvin is an absolute SI unit, so it's written K, not °K.

Can temperatures be negative in kelvin?

No. 0 K is absolute zero, the lowest possible temperature. The converter rejects anything below it.