Free Temperature Converter

Convert temperatures between Celsius, Fahrenheit, and Kelvin instantly with conversion formulas and quick reference values.

Convert Temperature

°F (Fahrenheit)
212 °F
K (Kelvin)
373.15 K

Celsius

100°C

Fahrenheit

212°F

Kelvin

373.15K

Quick Reference

Conversion Formulas

Celsius to Fahrenheit
°F = (°C × 9/5) + 32
Fahrenheit to Celsius
°C = (°F - 32) × 5/9
Celsius to Kelvin
K = °C + 273.15
Kelvin to Celsius
°C = K - 273.15

How to Use the Temperature Converter

Enter a Temperature Value

Type the temperature you want to convert into any of the three input fields: Celsius, Fahrenheit, or Kelvin. The converter accepts both positive and negative values.

See All Conversions Instantly

As you type, the equivalent temperatures in all three scales are calculated and displayed automatically. No need to click a button - results update in real-time.

Review the Conversion Formulas

Check the formula reference section to understand how each conversion is calculated. This is useful for learning or verifying manual calculations.

Use Quick Reference Values

Scroll down to see common temperature reference points like water freezing/boiling, body temperature, and room temperature in all three scales.

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Understanding Temperature Scales

Temperature is a measure of the average kinetic energy of particles in a substance. Three main scales are used worldwide: Celsius (used globally for everyday purposes), Fahrenheit (used primarily in the United States), and Kelvin (used in science). Understanding how to convert between these scales is essential for cooking, weather, science, and international communication.

Temperature Scales Explained

  • Celsius (°C): Water freezes at 0° and boils at 100°. Used worldwide except US.
  • Fahrenheit (°F): Water freezes at 32° and boils at 212°. Primary scale in the United States.
  • Kelvin (K): Absolute scale starting at absolute zero. Used in scientific contexts.

Frequently Asked Questions

How do I convert Celsius to Fahrenheit?

To convert Celsius to Fahrenheit, multiply the Celsius temperature by 9/5 (or 1.8) and add 32. The formula is: °F = (°C × 9/5) + 32. For example, 20°C = (20 × 1.8) + 32 = 68°F.

How do I convert Fahrenheit to Celsius?

To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit temperature and multiply by 5/9. The formula is: °C = (°F - 32) × 5/9. For example, 68°F = (68 - 32) × 5/9 = 20°C.

What is absolute zero?

Absolute zero is the lowest possible temperature where all molecular motion stops. It equals 0 Kelvin, -273.15°C, or -459.67°F. Nothing can be colder than absolute zero.

What is the difference between Celsius and Kelvin?

Celsius and Kelvin use the same scale increment (1°C = 1K), but have different zero points. 0°C is the freezing point of water, while 0K is absolute zero. To convert: K = °C + 273.15.

At what temperature are Celsius and Fahrenheit equal?

Celsius and Fahrenheit are equal at -40 degrees. This is the only temperature where both scales show the same number: -40°C = -40°F.