Temperature Conversion - Fahrenheit to Celsius The metric system uses the Celsius scale to measure temperature. However, temperatures are still measured on the Fahrenheit scale in the U.S. Water freezes at 0o Celsius and boils at 100o Celsius which is a difference of 100o. Water freezes at 32o Fahrenheit and boils at 212o Fahrenheit which is a difference of 180o. Therefore each degree on the Fahrenheit scale is equal to 100/180 or 5/9 degrees on the Celsius scale. How to convert Fahrenheit temperatures to Celsius Subtract 32o to adjust for the offset in the Fahrenheit scale. Multiply the result by 5/9. Example: convert 98.6o Fahrenheit to Celsius. 98.6 - 32 = 66.6 66.6 * 5/9 = 333/9 = 37o C. There is a mental math method to approximate the Fahrenheit to Celsius conversion. The ratio of 5/9 is approximately equal to 0.55555.... How to approximate the conversion of Fahrenheit temperatures to Celsius with mental math. Subtract 32o to adjust for the offset in the Fahrenheit scale. Divide the Celsius temperature by 2 (multiply by 0.5). Take 1/10 of this number (0.5 * 1/10 = 0.05) and add it from the number above. Example: convert 98.6o F to Celsius. 98.6 - 32 = 66.6 66.6 * 1/2 = 33.3 33.3 * 1/10 = 3.3 33.3 + 3.3 = 36.6 which is an approximation of the Celsius temperature Return to Top

#### Convert the Fahrenheit Temperature to Celsius

Round to the nearest degree.
 oF = oC