Explanation
In this example, the goal is to convert the Celsius temperatures shown in column B to Fahrenheit temperatures in column C. The solution shown in the worksheet above relies on the CONVERT function, which can convert a number in one measurement system to another. CONVERT is fully automatic and based on "from" and "to" unit strings. As long as the units valid options in the same category (weight, distance, temperature, etc.), CONVERT will automatically perform a conversion and return a numeric result.
Celsius to Fahrenheit
To convert from Celsius to Fahrenheit, use a "C" for Celsius and an "F" for Fahrenheit like this:
=CONVERT(B5,"C","F")
Note: unit strings are case-sensitive. Both the "C" and "F" must be uppercase.
Handling empty cells
If a cell in column B is empty, the CONVERT function will interpret the value as zero and return 32. To prevent this from happening, you can adjust the formula to test for a value first like this:
=IF(B5<>"",CONVERT(B5,"C","F"),"")
Here, the IF function is used to check if cell B5 is not empty. If so, the original CONVERT formula is run. If the cell is empty, IF returns an empty string ("") as a result, which looks like a blank cell in Excel. As an alternative, you can use the NOT and ISBLANK functions together like so:
=IF(NOT(ISBLANK(B5)),CONVERT(B5,"C","F"),"")
The result from this formula is exactly the same.
Fahrenheit to Celsius
To convert from Fahrenheit to Celsius, the formula would be:
=CONVERT(B5,"F","C")
Other conversions
You can use CONVERT to convert weight, distance, time, pressure, force, energy, power, magnetism, temperature, liquid, and volume. Unit strings must be valid and in the proper case. This page shows available options in each category.