Free Temperature Converter Online
Convert temperature between Celsius, Fahrenheit, and Kelvin.
Enter a temperature and click Convert to see results
Usage Examples
Boiling point of water
100°C = 212°F = 373.15 K
Freezing point of water
0°C = 32°F = 273.15 K
Normal human body temperature
37°C = 98.6°F = 310.15 K
Normal body temperature in Fahrenheit
98.6°F = 37°C = 310.15 K
Absolute zero — the lowest possible temperature
0 K = −273.15°C = −459.67°F
Comfortable room temperature
20°C = 68°F = 293.15 K
How to Use Temperature Converter
Enter a Temperature
Type a numeric temperature value. Negative values are supported for Celsius and Fahrenheit.
Select the Input Scale
Click the tab that matches your input unit: Celsius, Fahrenheit, or Kelvin.
View All Scales
See the temperature converted to all three scales, plus common reference points like water freezing and boiling.
Frequently Asked Questions
Basics
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 and add 32. For example, 100°C = 100 × 9/5 + 32 = 212°F.
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, 98.6°F = (98.6 - 32) × 5/9 = 37°C.
What is absolute zero?
Absolute zero is 0 Kelvin (−273.15°C or −459.67°F), the lowest possible temperature where all molecular motion theoretically stops.
Why does Kelvin not use degrees?
Kelvin is an absolute temperature scale based on thermodynamic absolute zero. Unlike Celsius and Fahrenheit, it's an absolute measurement, not a relative one, so it's written as "273.15 K" not "273.15°K".
Reference Points
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees: −40°C = −40°F. This is the only temperature where the two scales give the same numerical value.
What is normal room temperature?
Room temperature is typically considered 20-22°C (68-72°F). The converter shows reference points to help you understand where your temperature falls relative to common benchmarks.