Kelvin to Celsius Converter
Enter the value that you want to convert kelvin (K) to Celsius (°C) or Celsius to kelvin.Also written as K to °C conversion.
1 kelvin = -272.1500000 Celsius
Formula: °C = K − 273.15
K to °C — kelvin to Celsius
10 kelvin = -263.15000 Celsius
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Kelvin to Celsius for Practical Interpretation
Scientific instruments, satellite data, and physics journals report temperatures in Kelvin. Converting to Celsius (°C = K − 273.15) makes these values meaningful: the cosmic microwave background at 2.7 K = −270.5°C, liquid nitrogen at 77 K = −196°C, room temperature at 293 K = 20°C. Color temperature in photography uses Kelvin but photographers think in practical terms.
Kelvin to Celsius: The Essentials
The Kelvin Explained
The Kelvin scale begins at absolute zero (−273.15°C) — the theoretical lowest possible temperature where all molecular motion ceases.
Kelvin (K) is the SI base unit of temperature, essential in physics, chemistry, and engineering. It uses the same increment size as Celsius but starts at absolute zero. Key values: 0 K = absolute zero, 273.15 K = water freezes, 373.15 K = water boils. Kelvin is required for gas law calculations (PV=nRT), thermodynamic efficiency, color temperature in photography/lighting (5500K = daylight), and cryogenic engineering.
Understanding the Celsius
The Celsius scale was proposed by Swedish astronomer Anders Celsius in 1742, originally with 0° as the boiling point and 100° as freezing — later inverted.
Celsius (°C) is the most widely used temperature scale globally, adopted by every country except the United States for everyday use. It sets water's freezing point at 0°C and boiling point at 100°C at standard atmospheric pressure. The scale is used in weather forecasts, cooking, medicine (normal body temperature ≈ 37°C), scientific research, and industrial processes worldwide. Since 1954, it has been defined relative to the Kelvin scale: °C = K − 273.15.
Temperature Scales in Context
Temperature conversion is one of the few non-linear unit conversions people encounter daily. Celsius dominates scientific work and most countries, Fahrenheit remains standard in the US for weather and cooking, Kelvin is required in thermodynamics and gas law calculations, and Rankine appears in some US engineering applications. Converting between these scales requires formulas rather than simple multiplication.
kelvin to Celsius metric conversion table
| 0.01 K | = | -273.14000 °C |
| 0.1 K | = | -273.05000 °C |
| 1 K | = | -272.15000 °C |
| 2 K | = | -271.15000 °C |
| 3 K | = | -270.15000 °C |
| 4 K | = | -269.15000 °C |
| 5 K | = | -268.15000 °C |
| 6 K | = | -267.15000 °C |
| 7 K | = | -266.15000 °C |
| 8 K | = | -265.15000 °C |
| 9 K | = | -264.15000 °C |
| 10 K | = | -263.15000 °C |
| 11 K | = | -262.15000 °C |
| 12 K | = | -261.15000 °C |
| 13 K | = | -260.15000 °C |
| 14 K | = | -259.15000 °C |
| 15 K | = | -258.15000 °C |
| 16 K | = | -257.15000 °C |
| 17 K | = | -256.15000 °C |
| 18 K | = | -255.15000 °C |
| 19 K | = | -254.15000 °C |
| 20 K | = | -253.15000 °C |
| 30 K | = | -243.15000 °C |
| 40 K | = | -233.15000 °C |
| 50 K | = | -223.15000 °C |
| 60 K | = | -213.15000 °C |
| 70 K | = | -203.15000 °C |
| 80 K | = | -193.15000 °C |
| 90 K | = | -183.15000 °C |
| 100 K | = | -173.15000 °C |
| 200 K | = | -73.15000 °C |
| 300 K | = | 26.85000 °C |
| 400 K | = | 126.85000 °C |
| 500 K | = | 226.85000 °C |
| 600 K | = | 326.85000 °C |
| 700 K | = | 426.85000 °C |
| 800 K | = | 526.85000 °C |
| 900 K | = | 626.85000 °C |
| 1000 K | = | 726.85000 °C |
How to Convert K to °C (Kelvin to Celsius)?
We can convert kelvin to Celsius by using an example.
Example:
Convert 20 Kelvin to Celsius?
We know 1 Kelvin = -272.1500000 Celsius; 1 Celsius = 274.1500000 kelvin.
20 kelvin = ___°C
20 × -272.1500000 = -253.15000 °C (we know 1 kelvin = -272.1500000 Celsius)
Answer:
20 kelvin = -253.15000 Celsius
Kelvin to Celsius Conversion Method
Since Kelvin and Celsius use the same degree size, converting from Kelvin to Celsius requires only subtracting the 273.15 offset. This gives you the temperature relative to the freezing point of water rather than absolute zero.
- Note the temperature in Kelvin (K).
- Subtract 273.15 from the Kelvin value.
- The result is the temperature in degrees Celsius (°C).
Kelvin to Celsius: Astronomical & Lab Temperatures
Converting stellar and laboratory temperatures to the more familiar Celsius scale:
| Kelvin | Celsius |
|---|---|
| 0 K | −273.15 °C |
| 3 K | −270.15 °C |
| 77 K | −196 °C |
| 273.15 K | 0 °C |
| 373.15 K | 100 °C |
| 5778 K | 5504.85 °C |
| 6500 K | 6226.85 °C |
Worked Problems: Kelvin to Celsius
Question 1: The surface temperature of the Sun is approximately 5778 K. What is that in Celsius?
Solution:
Formula: °C = K − 273.15
°C = 5778 − 273.15
Answer: 5778 K = 5504.85 °C
Question 2: Liquid helium boils at 4.2 K. Convert to Celsius.
Solution:
°C = K − 273.15
°C = 4.2 − 273.15
Answer: 4.2 K = −268.95 °C
Question 3: A superconductor operates at 92 K. What is this in Celsius?
Solution:
°C = 92 − 273.15
°C = −181.15
Answer: 92 K = −181.15 °C
Question 4: Convert 310 K (approximate body temperature) to Celsius.
Solution:
°C = 310 − 273.15
°C = 36.85
Answer: 310 K = 36.85 °C
Question 5: A daylight-balanced light has a color temperature of 6500 K. Express in Celsius.
Solution:
°C = 6500 − 273.15
Answer: 6500 K = 6226.85 °C
Practice Conversions
Try solving these on your own to test your understanding:
- Convert 300 K to Celsius. (Answer: 26.85 °C)
- What is 77 K in Celsius? (Answer: −196.15 °C)
- Convert 500 K to Celsius. (Answer: 226.85 °C)
- The CMB radiation is 2.725 K. What is that in °C? (Answer: −270.425 °C)
- Convert 1000 K to Celsius. (Answer: 726.85 °C)
Color Temperature in Photography and Lighting
Color temperature — measured in Kelvin — describes the hue of light emitted by a source. A candle is about 1800 K (warm orange), household bulbs are 2700–3000 K (warm white), daylight is 5000–6500 K (neutral to cool white), and overcast sky can exceed 7000 K (bluish). Converting these to Celsius is not practically useful, but understanding the scale helps photographers set accurate white balance.
Stellar Classification by Temperature
Astronomers classify stars by surface temperature in Kelvin. O-type stars exceed 30,000 K, B-type are 10,000–30,000 K, our Sun (G-type) is about 5778 K, and cool M-type red dwarfs are 2400–3700 K. Converting to Celsius shows just how extreme stellar temperatures are — even the coolest red dwarf surface is over 2100 °C.
When to Use Kelvin vs. Celsius
Use Celsius for everyday measurements (weather, cooking, medical). Use Kelvin when performing scientific calculations involving thermodynamics, gas laws, radiation, or any formula that requires absolute temperature. A negative Kelvin value is physically impossible, which makes Kelvin the natural choice for physics equations that involve temperature ratios or differences from absolute zero.
Key Takeaways
- Formula: °C = K − 273.15.
- Simply subtract 273.15 from any Kelvin value to get Celsius.
- Negative Kelvin values are impossible — 0 K is the absolute minimum.
- The Sun's surface is about 5505 °C (5778 K).
- Color temperature in lighting is expressed in Kelvin.
- Kelvin and Celsius degrees are identical in size.
Kelvin to Celsius Conversion Formula
°C = K − 273.15
1 kelvin = -272.1500000 Celsius
1 Celsius = 274.1500000 kelvin
Frequently Asked Questions
How many Celsius are in 1 kelvin?
1 kelvin equals -272.15000 Celsius. Note: Temperature conversion uses a formula, not simple multiplication.
How do I convert kelvin to Celsius?
Use the conversion formula shown above. For example, -268.15 Celsius equals 5 kelvin. Temperature scales have different zero points, so a formula (not simple multiplication) is required.
How do I convert Celsius to kelvin?
Use the reverse formula. 1 Celsius equals 274.15000 kelvin. See the formula section above for the exact equation.
What is 10 kelvin in Celsius?
10 kelvin is equal to -263.15000 Celsius.
What is 100 kelvin in Celsius?
100 kelvin is equal to -173.15000 Celsius.