40°C to Fahrenheit
40 °C is 104.0 °F. 40 °C is high: as a body temperature it's a high fever (104 °F) worth medical attention, especially in children; as weather it's extreme heat.
104.0 °FFahrenheit
40 °CCelsius
×9/5 +32formula
Nearby temperatures
| °C | °F |
|---|---|
| 38 °C | 100.4 °F |
| 39 °C | 102.2 °F |
| 40 °C | 104.0 °F |
| 41 °C | 105.8 °F |
| 42 °C | 107.6 °F |
Body-temperature notes here follow the common clinical convention (normal ≈ 36.1–37.2 °C; fever ≥ 38.0 °C / 100.4 °F). Readings vary with the thermometer and time of day — this is general information, not medical advice.
Frequently asked questions
What is 40 degrees Celsius in Fahrenheit?
40°C equals 104.0°F.
Is 40°C a fever?
Yes — 38.0 °C (100.4 °F) and above is commonly counted as a fever.