Temperature Conversion - Celsius to Fahrenheit

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 Celsius scale is equal to 180/100 or 9/5 degrees on the Fahrenheit scale.

    How to convert Celsius temperatures to Fahrenheit
  • Multiply the Celsius temperature by 9/5.
  • Add 32o to adjust for the offset in the Fahrenheit scale.
  • Example: convert 37o C to Fahrenheit.
    37 * 9/5 = 333/5 = 66.6
    66.6 + 32 = 98.6o F

There is a mental math method to convert from Celsius to Fahrenheit. The ratio of 9/5 is equal to 1.8 and 1.8 is equivalent to 2 - 0.2

    How to convert Celsius temperatures to Fahrenheit with mental math.
  • Double the Celsius temperature (multiply by 2).
  • Take 1/10 of this number (2 * 1/10 = 0.2) and subtract it from the number above.
  • Add 32o to adjust for the offset in the Fahrenheit scale.
  • Example: convert 37o C to Fahrenheit.
    37 * 2 = 74
    74 * 1/10 = 7.4
    74 - 7.4 = 66.6
    66.6 + 32 = 98.6o F

Note: This lesson includes temperatures that use negative numbers. Negative numbers follow a pattern that is opposite of positive numbers. The number -20 is smaller than the number -10. Example of counting with negative and positive numbers: -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5.

    Example of converting negative Celsius temperatures to Fahrenheit
  • Convert -15o C to Fahrenheit.
  • -15 * 9/5 = -135/5 = -27
  • -27 + 32 = 5o F






Convert the Celsius Temperature to Fahrenheit

Round to the nearest degree.
oC = oF