Fahrenheit and Celsius Temperature Conversions

Thermometer
Thermometer. Michael Phillips/E+/Getty Images

Do you know what temperature it is? Temperature is reported in degrees either on the Fahrenheit scale or the Celsius scale. The United States favors Fahrenheit while most of the rest of the world chooses Celsius. It can be confusing when you travel to a country that reports temperature with the opposite scale and hard to interpret the weather forecast to dress appropriately for the conditions. Here is how to convert between the two systems.

If you'd rather use an online converter or check your math results, use our converter.
Fahrenheit and Celsius Converter Calculator

To convert Fahrenheit temperatures to Celsius:

  • Begin by subtracting 32 from the Fahrenheit number.
  • Divide the answer by 9.
  • Then multiply that answer by 5.

Here's an example: Change 95 degrees Fahrenheit to Celsius: 95 minus 32 is 63. Then, 63 divided by 9 is 7. Finally, 7 times 5 is 35 degrees Celsius.

To convert Celsius temperatures to Fahrenheit:

  • Begin by multiplying the Celsius temperature by 9.
  • Divide the answer by 5.
  • Now add 32.

Here's an example: Change 20 degrees Celsius to Fahrenheit: 20 times 9 is 180. Then 180 divided by 5 is 36. Finally, 36 plus 32 is 68 degrees Fahrenheit.

More Temperature Conversion Formulas: Converting Fahrenheit and Celsius to Kelvin and vice versa.

Degrees Fahrenheit Compared with Degrees Celsius

The Fahrenheit scale is more finely divided than the Celsius scale.

The difference of one degree Celsius is 1.8 degrees Fahrenheit, almost twice as much. This is given as one reason for people in the United States to continue to favor Fahrenheit. If you are used to the difference in degrees being smaller, you don't want to change to a scale where they are more significant.

For example, when it is 32° F outside it is at the freezing point for water and it's likely that ice will form or melt. With Celsius, the freezing point is 0°C. Saying that the temperature is 0°C without adding a decimal could mean a temperature range of 3.6 degrees Fahrenheit, from 30.2° to 33.8°F

Temperature Trivia

  • Celsius uses the freezing point of water at sea level as the zero point, and the boiling point of water at sea level for 100 degrees. This is was refined in 1954 with the scale defined based on the value of absolute zero Kelvin as −273.15° C and 0° C being the triple point of specially purified water.
  • The Celsius scale is named after Swedish astronomer Anders Celsius who developed a similar scale in 1742, but in reverse with 100 being the freezing point of water and 0 the boiling point.
  • In Fahrenheit, water freezes at 32 degrees and boils at 212 degrees.
  • The Fahrenheit scale was proposed in 1724 by the German physicist Daniel Gabriel Fahrenheit.
  • The temperature of -40° is the same on both scales.
  • The Celsius scale was historically called Centigrade.
  • Most countries switched from Fahrenheit to Celsius in the 1960's when they adopted the metric system. The United States and a few other countries are hold-outs, using Fahrenheit for daily activities although scientists in the United States use Celsius.

Heat Index

You can use the heat index to determine whether it's too hot for athletic activities. It is used by schools and training facilities to set rules about when to have athletes exercise outdoors and how hard to exercise.

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