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Temperature Converter

Convert between temperature units

About the Calculator

Temperature conversions show up in everyday life more than people expect. This converter makes it easy to move between Celsius, Fahrenheit, and Kelvin without memorizing formulas. Use it when you are traveling, checking a recipe, or reading a weather report in a different scale. It is also useful for students and science work, since Kelvin is the standard in many formulas. Enter a value, pick the units, and you get an instant answer you can trust. It saves time and helps you avoid common mistakes like mixing scales. When the numbers are clear, decisions feel simpler, whether you are cooking, studying, or planning a trip.

25°C

77.00°F

Reference Points

Water Freezes: 0°C / 32°FWater Boils: 100°C / 212°F

The Formula

°F = (°C × 9/5) + 32 | °C = (°F - 32) × 5/9 | K = °C + 273.15

How to Calculate Manually

  1. 1

    Celsius to Fahrenheit: Multiply by 9/5 (or 1.8), then add 32.

  2. 2

    Fahrenheit to Celsius: Subtract 32, then multiply by 5/9.

  3. 3

    Celsius to Kelvin: Add 273.15.

  4. 4

    Kelvin to Celsius: Subtract 273.15.

  5. 5

    For Fahrenheit to Kelvin, first convert to Celsius, then to Kelvin.

Examples

Convert 25°C to Fahrenheit

(25 × 9/5) + 32 = 45 + 32 = 77°F

Convert 98.6°F to Celsius

(98.6 - 32) × 5/9 = 66.6 × 0.556 = 37°C

Convert 0°C to Kelvin

0 + 273.15 = 273.15 K

💡 Tips

  • Normal body temperature is 98.6°F or 37°C.
  • Water freezes at 32°F / 0°C and boils at 212°F / 100°C.
  • Absolute zero (0 K) is -273.15°C or -459.67°F.
  • The two scales meet at -40: -40°C = -40°F.

🎉 Fun Facts

  • The Fahrenheit freezing point mistake: Daniel Fahrenheit set 0°F as the coldest temperature he could create (salt-ice mixture) and 96°F as human body temperature; but he miscalculated body temp (actually 98.6°F), making his scale based on errors that stuck for 300 years.
  • The only temperature all scales agree: at -40 degrees, Fahrenheit and Celsius are exactly the same (-40°F = -40°C), the only point where both scales intersect, creating the world's most useless temperature trivia fact.
  • Absolute zero can never be reached: absolute zero (-273.15°C or -459.67°F or 0 Kelvin) is theoretically the coldest possible temperature where atoms stop moving; but quantum mechanics prevents us from ever actually reaching it, only getting extremely close (scientists have achieved 0.0000000001 K).
  • The world uses Celsius... except: only 7% of the world's population uses Fahrenheit (US, some Caribbean islands, Palau, Micronesia) while 93% uses Celsius; yet US weather forecasts, cooking recipes, and medical thermometers remain stubbornly Fahrenheit.
  • The sun's core temperature: the sun's core is approximately 15 million °C (27 million °F); but the surface is only 5,500°C (9,932°F), while the corona (outer atmosphere) mysteriously spikes back up to 1-2 million °C, a puzzle scientists are still trying to solve.
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