Temperature conversion
Celsius to Kelvin converter
Convert °C to K instantly, choose the displayed precision, and verify the result with the formula and reference table below.
Kelvin (K)
Rounded for display only; calculations retain full precision.
Rounding and precision rules
- Convr calculates first and rounds the displayed result only once, at the final step.
- The default is a maximum of 6 decimal places; trailing zeros are removed.
- Very small values that would appear as zero, and values of 10¹² or more, use scientific notation.
- Display precision is not measurement uncertainty. For scientific, engineering, or regulated work, retain only the digits justified by the source measurement.
Practical context
Understanding this conversion
Celsius is convenient for weather, laboratory observations, and everyday temperatures. Kelvin is the SI unit of thermodynamic temperature and is required in many physics, chemistry, and engineering equations.
Only an offset is needed because a change of one degree Celsius has the same magnitude as a change of one kelvin. Absolute zero is −273.15 °C, corresponding to 0 K.
Reviewed August 16, 2026.
Calculation
Celsius to Kelvin formula
K = °C + 273.15
Calculations retain full precision and the result is rounded only for display.
Worked example
For 25 °C, the result is 298.15 K. Substitute 25 °C into the formula to obtain 298.15 K.
Temperature scales use both scale and offset, so this conversion is not a simple multiplication.
Celsius to Kelvin reference table
Common values rounded to a maximum of 6 decimal places.
| Celsius (°C) | Kelvin (K) |
|---|---|
| 1 °C | 274.15 K |
| 5 °C | 278.15 K |
| 10 °C | 283.15 K |
| 50 °C | 323.15 K |
| 100 °C | 373.15 K |
Understanding the units
About Celsius and Kelvin
Celsius (°C)
The Celsius scale sets water’s freezing point at 0 °C and boiling point at 100 °C at standard atmospheric pressure.
Kelvin (K)
The kelvin is the SI unit of thermodynamic temperature and begins at absolute zero.
When this conversion is useful
Celsius to Kelvin conversion is useful for weather reports, cooking instructions, laboratory readings, engineering specifications, and scientific data. It lets you compare the same temperature reading across documents, tools, or standards that use different units.
Learn with Convr
Conversion guides
Celsius, Fahrenheit, Kelvin, and Rankine Explained
Learn how the four major temperature scales differ, why offsets matter, and which formulas convert between them correctly.
Read guide →FoundationsSignificant Figures and Rounding in Unit Conversions
Learn when to round conversion results, how significant figures preserve measurement meaning, and why more decimals do not guarantee more accuracy.
Read guide →Answers at a glance
Frequently asked questions
Why do I add 273.15 to Celsius?
The Celsius and kelvin scales have equal-sized increments, but their zero points differ by exactly 273.15 degrees.
Is the kelvin symbol written with a degree sign?
No. The SI unit is written K, not °K, and its name is normally lowercase when spelled out.
How does Convr round Celsius to Kelvin results?
Convr keeps full numeric precision during the calculation and rounds only the displayed result. The default is a maximum of 6 decimal places, with selectable precision on this page.
Can I convert negative or decimal celsius values?
Yes. The converter accepts positive, negative, decimal, and scientific-notation values. Negative values are physically meaningful for some scales, such as temperature, but not for every measured quantity.
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