Fahrenheit and Celsius

In the United States, we regularly use Fahrenheit as our temperature gauge. We cook our meals and check the weather both in Fahrenheit. Outside of the United States and in the scientific world, you will most likely see temperature measured in Celsius.

When looking at a medication’s storage procedure, the packaging might be in Celsius only so it is important to calculate temperature conversions and know your freezing points, room range, and boiling points in both Celsius (C°) and Fahrenheit (F°).

Convert Fahrenheit to Celsius

To convert a temperature from Fahrenheit to Celsius, subtract 32 from the temperature given, then multiply by ⁵⁄₉.

(°F – 32) * ⁵⁄₉

We can test out this formula the freezing and boiling points from Fahrenheit to Celsius.

Freezing point: (32°F – 32) * ⁵⁄₉ = 0°C

Boiling point: (212°F -32) * ⁵⁄₉ = 100°C

Convert Celsius to Fahrenheit

Now let’s convert temperatures Celsius to Fahrenheit. Notice the difference in the fraction and the placement of the numbers from the formula above.

(°C * ⁹⁄₅) + 32

Again, we can test this out with the freezing and boiling points.

Freezing point: (0°C * ⁹⁄₅) + 32 = 32°F

Boiling point: (100°C * ⁹⁄₅) + 32 = 212°F

You can work these problems using the decimal equivalent of the fractions if you prefer. Instead of ⁵⁄₉, use .5556 and 1.8 instead of ⁹⁄₅. Since you are allowed to use a calculator for the exam, using decimals can be simpler.

Temperature Example

The refrigerator where the insulin is stored at Matty’s pharmacy is supposed to stay around 6°C. What is this temperature converted to Fahrenheit? Round your answer.

(6°C * 1.8) + 32

10.8 + 32 = 42.8

Since the decimal is .8, we round up so the answer is the insulin refrigerator should be kept around 43°F.

Need a refresher on when to round up or down? Visit Pass the Math Review’s Rounding Lesson.