How to Calculate Month-over-Month Growth in Excel

Calculate month-over-month growth, the compound monthly growth rate over a period, and how many months went backwards.

You will learn to

• Calculate growth from one month to the next
• Calculate a compound monthly growth rate
• Count the months that declined

How it works

Month-over-month growth is this month ÷ last month − 1: =B10/B9-1, formatted as a percentage. Individual months bounce around, so for a period it’s better to report the compound monthly growth rate (CMGR): (last ÷ first)^(1 ÷ number of months between them) − 1. It’s the steady monthly rate that would take you from the first value to the last.

Don’t simply average the monthly percentages — a −10% month followed by a +10% month averages 0% but leaves you 1% down. And count the down months too: =SUMPRODUCT(--(B3:B10<B2:B9)) shows how bumpy the growth was.

=B10/B9-1