104°F to Celsius
104 °F is 40.0 °C. 104 °F is a high fever — exactly 40 °C — worth medical attention, especially in children.
Convert any temperature
Nearby temperatures
| °F | °C |
|---|---|
| 102 °F | 38.9 °C |
| 103 °F | 39.4 °C |
| 104 °F | 40.0 °C |
| 105 °F | 40.6 °C |
| 106 °F | 41.1 °C |
What this reading means
104.0°F (40.0°C) is a high fever. Readings from about 102.3°F (39.1°C) to 104°F (40°C) fall in the high range. A high fever that persists, or that comes with concerning symptoms, is generally worth discussing with a healthcare professional.
Measurement method changes the number, too: forehead and ear readings can differ from oral, and rectal readings (used for infants) tend to run a little higher. For the same person, a 0.5–1°F difference between methods is normal.
How to convert °F to °C
The exact formula is °C = (°F − 32) × 5/9. For 104.0°F: (104.0 − 32) × 5/9 = 72.0 × 5/9 = 40.0°C. To go the other way, °F = (°C × 9/5) + 32. A quick mental shortcut for Fahrenheit to Celsius: subtract 30 and halve it — close enough for a rough idea, though not exact.
Frequently asked questions
What is 104 degrees Fahrenheit in Celsius?
104°F equals 40.0°C.
Is 104°F a fever?
Yes — 100.4 °F (38.0 °C) and above is commonly counted as a fever.