How to compute a doubling with percentages

What does it mean when someone says: We are going to grow revenues

14% every year ? 

10% every year ?

5% every year ?

There is a very simple trick that allows you to quickly translate it in terms of doubling.

(free pic under CC)

Just take 70 and divide by the percentage number:


70/14 = 5 yrs

70/10 = 7 yrs

70/ 5 = 14 yrs


So when someone says:

We are going to grow 14% every year, this person is saying that revenues will double in 5 yrs.

 in short:

14% every year ? --> 2x in 5 yrs

10% every year ? --> 2x in 7 yrs


5% every year ? --> 2x in 14 yrs