Fahrenheit to Celsius Calculator
Temperature ratings appear on nearly every electrical component, from wire insulation to motor nameplates. When those ratings are listed in Celsius but your thermometer reads Fahrenheit, a quick conversion keeps you from guessing whether conditions are within spec.
Enter a Fahrenheit temperature and this calculator returns the Celsius equivalent along with the Kelvin value. It works for any temperature, including negative values.
Conversion Formula
°C = (°F − 32) × 5/9
Subtract 32, then multiply by 0.5556
For a quick mental estimate, subtract 30 and divide by 2. That gives a rough Celsius value within a few degrees for everyday temperatures.
Frequently Asked Questions
What is the formula to convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply the result by 5/9. The formula is C = (F - 32) x 5/9. For example, 72 degrees F minus 32 is 40, and 40 times 5/9 equals 22.22 degrees C.
Why do electricians need to convert Fahrenheit to Celsius?
Many electrical components have temperature ratings specified in Celsius, such as wire insulation limits, motor operating temperatures, and ambient temperature deratings in the NEC. Converting between Fahrenheit and Celsius ensures you stay within safe operating ranges.
At what temperature are Fahrenheit and Celsius equal?
Fahrenheit and Celsius are equal at -40 degrees. At that point, -40 degrees F equals exactly -40 degrees C. This is the only temperature where the two scales intersect.