-21f to c

Step 1: Identify the conversion factor

The conversion factor from fahrenheit to celsius is:

1 fahrenheit = 1.402095 celsius

Step 2: Set up the calculation

To convert -21 fahrenheit to celsius, multiply -21 by the conversion factor 1.402095:

-21×1.402095

Step 3: Calculate

-21×1.402095=-29.444

Step 4: Round the result

The result is approximately: -29.44 celsius

Final Answer:

-21 fahrenheit is approximately -29.44 celsius.