Here's how to convert 40 degrees Celsius to Fahrenheit:

Formula:

* F = (C * 9/5) + 32

Calculation:

1. Multiply Celsius by 9/5: 40 * 9/5 = 72

2. Add 32: 72 + 32 = 104

Answer: 40 degrees Celsius is equal to 104 degrees Fahrenheit.