How the temperature converter works
The Celsius and Fahrenheit scales differ in both their zero point and their degree size. A Celsius degree is 1.8 times larger than a Fahrenheit degree.
°F = °C × 9 ÷ 5 + 32
K = °C + 273.15 · °R = K × 1.8
Kelvin and Rankine are absolute scales that start at absolute zero (−273.15 °C or −459.67 °F), the lowest possible temperature. Kelvin uses Celsius-sized degrees and is the SI unit used in science; Rankine uses Fahrenheit-sized degrees and appears in some US engineering work. The Celsius and Fahrenheit scales cross at −40, where −40 °C equals −40 °F.
Worked example
Normal body temperature of 98.6 °F is (98.6 − 32) × 5/9 = 37 °C, or 310.15 K. An oven at 350 °F is 176.67 °C, usually rounded to 180 °C in recipes. Water boils at 212 °F (100 °C) at sea level.
Frequently asked questions
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. 68 °F is 20 °C.
What temperature is the same in Fahrenheit and Celsius?
−40 degrees.
What is absolute zero?
0 K, −273.15 °C or −459.67 °F, the point at which a system has minimum thermal energy.
Is 37 °C a fever?
No; it is a normal average. A fever is generally 38 °C (100.4 °F) or higher.
Updated October 2026. Results are estimates for education, not financial or medical advice. All math runs in your browser; nothing you type is sent anywhere.