Kelvin ↔ Celsius Converter

Convert between Kelvin and Celsius instantly

Enter Kelvin value to convert to Celsius
Enter Celsius value to convert to Kelvin
Conversion Result
273.15 K = 0 °C
Water Freezing Point • 32 °F • 491.67 °R

📚 Kelvin ↔ Celsius Conversion Details

Kelvin to Celsius Formula

°C = K - 273.15

To convert Kelvin to Celsius, subtract 273.15 from the Kelvin temperature.

Celsius to Kelvin Formula

K = °C + 273.15

To convert Celsius to Kelvin, add 273.15 to the Celsius temperature.

Bidirectional Conversion

This converter works both ways simultaneously:

  • Type in Kelvin → Celsius updates automatically
  • Type in Celsius → Kelvin updates automatically
  • No buttons to click - works as you type

Key Temperature Points

  • Absolute Zero: 0 K = -273.15 °C
  • Water Freezes: 273.15 K = 0 °C
  • Room Temp: ~293.15 K = ~20 °C
  • Water Boils: 373.15 K = 100 °C

🌡️ How This Converter Works

This is a bidirectional converter that works in real-time:

  1. Kelvin → Celsius: When you type in the Kelvin field, the Celsius field automatically updates
  2. Celsius → Kelvin: When you type in the Celsius field, the Kelvin field automatically updates
  3. No swapping needed: Both conversions happen simultaneously
  4. Real-time: Updates happen as you type, no button clicks required
// Bidirectional Conversion Logic:
celsius = kelvin - 273.15
kelvin = celsius + 273.15

// Example 1: Type "300" in Kelvin
celsius = 300 - 273.15 = 26.85°C

// Example 2: Type "25" in Celsius
kelvin = 25 + 273.15 = 298.15 K

📊 Important Temperature Reference Points

Description Kelvin (K) Celsius (°C) Fahrenheit (°F)
Absolute Zero 0 K -273.15 °C -459.67 °F
Water Freezing Point 273.15 K 0 °C 32 °F
Room Temperature 293.15 K 20 °C 68 °F
Human Body Temperature 310.15 K 37 °C 98.6 °F
Water Boiling Point 373.15 K 100 °C 212 °F

❓ Frequently Asked Questions

Q: What is the relationship between Kelvin and Celsius?

A: The Kelvin scale starts at absolute zero (0 K) and uses the same degree size as Celsius. To convert: °C = K - 273.15.

Q: What is 0 Kelvin in Celsius?

A: 0 Kelvin is -273.15 °C, which is absolute zero - the coldest possible temperature.

Q: Why is 273.15 used in the conversion?

A: 273.15 is the difference between the Kelvin and Celsius scales. 0 °C (water freezing) equals 273.15 K.

Q: Is Kelvin ever negative?

A: No, the Kelvin scale starts at absolute zero (0 K) and only has positive values. Celsius can be negative.