What temperature do the Celsius and Fahrenheit scales read the same?

What temperature do the Celsius and Fahrenheit scales read the same?

The formulas for converting between degree Celsius and degree Fahrenheit are:

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

To find the temperature when both are equal, we use an old algebra trick and just set ºF = ºC and solve one of the equations.

°C = (°C * 9/5) + 32
°C – (°C * 9/5) = 32
-4/5 * °C = 32
°C = -32 * 5/4
°C = -40

°F = (°F * 9/5) + 32
°F – (°F * 9/5) = 32
-4/5 * °F = 32
°F = -32 * 5/4
°F = -40

So the temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.