What Is a Function

Part of the Fundamentals section of Coddy's Excel journey — lesson 22 of 42.

Imagine adding up a column of 50 numbers with what you know so far: =A1+A2+A3+A4+A5..., all the way to A50. It works, but it's painful to type, easy to get wrong, and breaks the moment you add row 51.

Excel has a better way: functions, ready-made calculations with a name. The most famous one adds numbers up:

=SUM(A1:A5)

Read it in three parts. SUM is the function name, what to do. The parentheses ( ) always follow the name and hold what the function works on. And A1:A5 is the argument, here a range, shorthand for "every cell from A1 down to A5".

Why is this better than =A1+A2+A3+A4+A5? It's shorter, it's harder to mistype, and a range is easy to stretch: change it to A1:A50 and you've covered 50 rows in one edit. Functions also start with = like every formula, SUM(A1:A5) without the = is just text.

In this chapter you'll meet the everyday five: SUM, AVERAGE, MIN, MAX and COUNT. Learn the pattern once, name, parentheses, range, and every other function will feel familiar.

Try it yourself

This lesson doesn't include a code challenge.