100 Fahrenheit to Celsius
100 °F ≈ 37.78 °C
100 degrees Fahrenheit is approximately 37.78 degrees Celsius.
How to convert 100 °F to °C
Use the formula °C = (°F − 32) × 5/9:
°C = (100 − 32) × 5/9°C = 68 × 5/9°C = 37.777778
So 100 °F = 37.777778 °C, or about 37.78 °C rounded.
Rounded values and quick estimate
- Rounded to a whole number: 38 °C
- Rounded to one decimal place: 37.8 °C
Quick mental estimate: subtract 30 and halve it. For 100 °F that gives about 35 °C — off by 2.78 °C (7.4%). Use the exact formula when precision matters.
100 Fahrenheit in other units
37.78 °C falls in the range used for human body temperature. As air temperature it is extreme heat. As a body reading, about 36.1–37.2 °C is typical for healthy adults, 38 °C (100.4 °F) and above is commonly considered a fever, and below 35 °C (95 °F) is considered hypothermia.
- Celsius
- 37.78 °C
- Degrees Réaumur
- 30.22 °Ré
- Degrees Delisle
- 93.33 °De
- Degrees Newton
- 12.47 °N
- Degrees Rømer
- 27.33 °Rø
- Kelvin
- 310.93 K
- Rankine
- 559.67 °R
General information only, not medical advice. If you are concerned about a temperature reading, contact a healthcare professional.
100 °F and nearby values
About fahrenheit and celsius
The Fahrenheit scale puts water’s freezing point at 32 °F and boiling point at 212 °F. It is the everyday temperature scale in the United States.
The Celsius scale sets the freezing point of water at 0 °C and its boiling point at 100 °C (at sea level). It is used for everyday temperatures in almost every country.
Related conversions
Frequently asked questions
What is 100 Fahrenheit in Celsius?
100 degrees Fahrenheit is about 37.78 degrees Celsius (100 °F ≈ 37.78 °C).
How do you convert 100 °F to °C?
Apply °C = (°F − 32) × 5/9: °C = (100 − 32) × 5/9, °C = 68 × 5/9, °C = 37.777778.
How many degrees Fahrenheit is 37.78 °C?
37.78 °C is about 100 degrees Fahrenheit.