Temperature Converter Guide: Celsius, Fahrenheit & Kelvin
The world uses three main temperature scales. Understanding the conversions between them is essential for cooking, weather, science, and travel.
Conversion Formulas
Reference Temperature Points
| Temperature | °C | °F | K |
|---|---|---|---|
| Absolute zero | −273.15 | −459.67 | 0 |
| Water freezes | 0 | 32 | 273.15 |
| Room temperature | 22 | 71.6 | 295.15 |
| Body temperature | 37 | 98.6 | 310.15 |
| Water boils | 100 | 212 | 373.15 |
Frequently Asked Questions
What is the formula to convert Celsius to Fahrenheit?
°F = (°C × 9/5) + 32. Example: 100°C = (100 × 1.8) + 32 = 180 + 32 = 212°F. Quick estimate: double the Celsius and add 30 (gives a rough result).
What is the formula to convert Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. Example: 98.6°F = (98.6 − 32) × 5/9 = 66.6 × 0.556 = 37°C (normal body temperature).
What is absolute zero?
Absolute zero is the lowest possible temperature — 0 Kelvin = −273.15°C = −459.67°F. At absolute zero, all molecular motion ceases. It cannot be reached in practice, only approached asymptotically.
What is the Kelvin scale?
Kelvin (K) is the SI unit of temperature, used in science. It starts at absolute zero (K = 0) and has the same degree size as Celsius. K = °C + 273.15. So water freezes at 273.15 K and boils at 373.15 K. Kelvin never uses the degree symbol (°).
At what temperature are Fahrenheit and Celsius equal?
At −40°. Both scales meet at −40°C = −40°F. This is the only point where they are equal. You can verify with either formula: (−40 × 9/5) + 32 = −72 + 32 = −40.
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