40 °C = 104 °F
40 degrees Celsius is 104 degrees Fahrenheit exactly.
- Exact
- 104 °F
- Rounded
- 104 °F
- Formula
- 40 × 9/5 + 32
Convert any other temperature
Type in either box; the other follows, and the scale moves with it. Works for decimals and, for temperatures, numbers below zero.
Around 40 °C
Celsius to Fahrenheit for the whole numbers either side of 40, rounded to one decimal place. Each row opens its own page.
| Degrees Celsius | Degrees Fahrenheit |
|---|---|
| 35 °C | 95 °F |
| 36 °C | 96.8 °F |
| 37 °C | 98.6 °F |
| 38 °C | 100.4 °F |
| 39 °C | 102.2 °F |
| 40 °C | 104 °F |
| 41 °C | 105.8 °F |
| 42 °C | 107.6 °F |
| 43 °C | 109.4 °F |
| 44 °C | 111.2 °F |
| 45 °C | 113 °F |
How to convert Celsius to Fahrenheit
The formula
°F = °C × 9/5 + 32. The two scales start from different zero points, so there is a subtraction as well as a multiplication.
Worked through for 40
Multiply by 9/5 (1.8): 40 × 1.8 = 72. Add 32: 72 + 32 = 104. Rounded, that is 104 °F.
In your head
Double it and add 30: 20 °C → 40 + 30 = 70 °F (close enough for weather).
Questions
What is 40 °C in Fahrenheit?
40 degrees Celsius is 104 degrees Fahrenheit, or 104 °F rounded to one decimal place.
How do you convert degrees Celsius to degrees Fahrenheit?
Use 40 × 9/5 + 32, which gives 104. For a quick estimate: Double it and add 30: 20 °C → 40 + 30 = 70 °F (close enough for weather).
Is 40 °C hot or cold?
40 °C is 104 °F: a fever if it is a body temperature, and a heatwave as weather.
What is 40 °F in Celsius?
Going the other way, 40 °F is 4.4 °C. The reverse conversion has its own page and converter.
Is the answer exact?
Yes. 40 °C converts to exactly 104 °F; the rounded figure is only for convenience.