Temperature Conversion°C → K

Celsius to Kelvin Converter

Convert celsius (°C) to kelvin (K) using documented conversion factors. Includes interactive calculations, conversion formula, worked steps, and common reference tables.

Temperature Converter

Live Interactive Calculator

Value to Convert

Source Unit

Converted Result

274.15K

Target Unit

Summary:1 °C = 274.15 K

Formula:K = °C + 273.15

Conversion Formula

To convert from celsius to kelvin, apply the mathematical formula:

K = °C + 273.15

Where °C represents celsius and K represents kelvin.

Conversion Factor

The base relationship defined under primary measurement standards:

1 °C change equals 1 K change, offset by 273.15.

Reference: BIPM SI Brochure / NIST SP 811

Understanding Temperature Scale Conversions

Unlike length or weight conversions, which are purely multiplicative ratios, temperature conversions between Celsius and Kelvin require an affine transformation (both multiplication and an offset) because their zero points are defined differently:

Water Freezing Point

0 °C = 32 °F = 273.15 K

Water Boiling Point

100 °C = 212 °F = 373.15 K

Crossover Parity

-40 °C = -40 °F

The difference between freezing and boiling is 100 degrees on the Celsius scale and 180 degrees on the Fahrenheit scale. This yields the exact step ratio:

180 ÷ 100 = 9/5 = 1.8 (Each 1 °C change equals 1.8 °F change)

To convert from Celsius to Fahrenheit, multiply the Celsius temperature by 1.8 (or 9/5) and then add the 32° offset. To convert from Fahrenheit to Celsius, subtract the 32° offset first and then multiply by 5/9 (approximately 0.5556).

How to Convert Celsius to Kelvin

Converting measurements between celsius and kelvin follows a structured calculation process:

Identify the quantity in celsius (°C) that you wish to convert.
Apply the temperature scale formula: K = °C + 273.15.
The resulting value is the equivalent amount expressed in kelvin (K).

Common Celsius to Kelvin Reference Table

Frequently referenced values calculated using documented measurement conversion factors.

Celsius (°C)	Kelvin (K)	Arithmetic Expression
-273.15 °C	0 K	-273.15 + 273.15
-100 °C	173.15 K	-100 + 273.15
0 °C	273.15 K	0 + 273.15
20 °C	293.15 K	20 + 273.15
25 °C	298.15 K	25 + 273.15
100 °C	373.15 K	100 + 273.15
500 °C	773.15 K	500 + 273.15
1,000 °C	1,273.15 K	1,000 + 273.15

Worked Calculation Examples

Practical step-by-step calculations showing how to convert celsius to kelvin with exact mathematical equations.

Example 1-273.15 °C → K

-273.15 °C + 273.15 = 0 K

Application context: Absolute zero (0 K)

Calculation Steps:

1.Add 273.15 to -273.15 °C: -273.15 + 273.15 = 0 K.

Calculated Output:0 K

Example 20 °C → K

0 °C + 273.15 = 273.15 K

Application context: Water freezing point (273.15 K)

Calculation Steps:

1.Add 273.15 to 0 °C: 0 + 273.15 = 273.15 K.

Calculated Output:273.15 K

Example 325 °C → K

25 °C + 273.15 = 298.15 K

Application context: Standard ambient temperature for chemical reactions (298.15 K)

Calculation Steps:

1.Add 273.15 to 25 °C: 25 + 273.15 = 298.15 K.

Calculated Output:298.15 K

Example 4100 °C → K

100 °C + 273.15 = 373.15 K

Application context: Water boiling point (373.15 K)

Calculation Steps:

1.Add 273.15 to 100 °C: 100 + 273.15 = 373.15 K.

Calculated Output:373.15 K

About the Units

Authoritative technical specifications and historical definitions for both units.

Source Unit

Celsius (°C)

The Celsius temperature scale is defined such that 0 °C is 273.15 K (the approximate freezing point of water) and 100 °C is 373.15 K. An interval of 1 °C equals 1 Kelvin.

System: metric

Base Unit: kelvin

Authoritative Source: BIPM SI Brochure / NIST SP 811

Target Unit

Kelvin (K)

The Kelvin is the SI base unit of thermodynamic temperature. Absolute zero (0 K) corresponds to the complete absence of classical thermodynamic thermal energy.

System: si

Base Unit: kelvin

Authoritative Source: BIPM 26th CGPM Resolution 1

Inverse Conversion