°C = K − 273.15
Temperature scales require both a scale and an offset.Conversion lab / temperature
Kelvin to Celsius Converter
Convert kelvins to degrees Celsius using the exact 273.15 offset.
Kelvin to Celsius Converter: Express an absolute laboratory temperature in the Celsius notation used on everyday thermometers. Subtract the fixed separation between the scale origins. This is useful when a science problem gives kelvin but asks you to describe the same conditions in familiar Celsius terms. Runs 100% locally in your browser with zero server file uploads.
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Result / live
-272.15
°Cdegrees Celsius
0 K-273.15 °C
233.15 K-40 °C
273.15 K0 °C
293.15 K20 °C
373.15 K100 °C
Kelvins to degrees Celsius conversion table
| kelvins (K) | degrees Celsius (°C) |
|---|---|
| 0 K | -273.15 °C |
| 20 K | -253.15 °C |
| 40 K | -233.15 °C |
| 60 K | -213.15 °C |
| 80 K | -193.15 °C |
| 100 K | -173.15 °C |
| 120 K | -153.15 °C |
| 140 K | -133.15 °C |
| 160 K | -113.15 °C |
| 180 K | -93.15 °C |
| 200 K | -73.15 °C |
| 220 K | -53.15 °C |
| kelvins (K) | degrees Celsius (°C) |
|---|---|
| 233.15 K | -40 °C |
| 240 K | -33.15 °C |
| 260 K | -13.15 °C |
| 273.15 K | 0 °C |
| 280 K | 6.85 °C |
| 293.15 K | 20 °C |
| 300 K | 26.85 °C |
| 320 K | 46.85 °C |
| 340 K | 66.85 °C |
| 360 K | 86.85 °C |
| 373.15 K | 100 °C |
Rounded to seven significant digits; the converter above uses the full factor.
From an absolute reading to Celsius
Use T for temperature in kelvin and C for degrees Celsius. C = T − 273.15. If an exercise supplies 310.15 K, subtract 273 to reach 37.15, then subtract the remaining 0.15: the result is 37 °C. The operation translates the zero point without stretching the intervals, so a change of one kelvin remains a change of one Celsius degree. This affine shift is not proportional: zero kelvin does not become zero Celsius.
The official NIST guide (https://www.nist.gov/pml/owm/si-units-temperature) documents this relationship. Write 310.15 K rather than 310.15 °K; kelvin has no degree sign, while the converted Celsius symbol does. To express a 10 K interval on the Fahrenheit scale, multiply by 9/5 to obtain 18 °F; the same interval is 10 °C.
Comparing readings across all three scales
At 233.15 K the subtraction gives −40 °C, which is also −40 °F. Solving the Fahrenheit relation x = 1.8x + 32 yields that shared reading. Do not assume equal numerical readings elsewhere: at 273.15 K the Celsius result is 0 °C and the Fahrenheit result is 32 °F. Retain the unit when copying a bare number into notes.
How to use it
- Enter the temperature in kelvins.
- Read the converted degrees Celsius value as it updates.
- Use the common values or open the reverse conversion to cross-check.
Privacy & limitations
Your value never leaves this browser. JavaScript floating-point arithmetic can round the last displayed digit; this general utility is not a substitute for calibrated or regulated measurement systems.
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Frequently asked questions
Why can a positive kelvin reading become negative Celsius?
Any kelvin input below 273.15 K lies below Celsius zero. For example, 250 K − 273.15 = −23.15 °C. The minus sign locates the reading below the Celsius origin; it does not mean the input was a negative absolute temperature.
What is 0 K on a Celsius thermometer?
It corresponds to −273.15 °C, the absolute-zero boundary used by this converter. Entering a value below 0 K is rejected here. Zero Celsius, in contrast, corresponds to 273.15 K and is not the bottom of the scale.
Should a 15 K cooling interval become −258.15 °C?
No. A cooling interval of 15 K has magnitude 15 °C. If the signed change is −15 K, it is −15 °C. Subtracting 273.15 converts a position on the kelvin scale, not the distance between two positions.
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