Investing
Doubling time
Divide 72 by the annual percentage return to estimate the doubling time.
The Formula
Years = 72 / rate percent
Divide 72 by the annual percentage return to estimate the doubling time.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| r | Annual return | rate | Return as a percentage, such as 8 for 8%. |
What Each Symbol Means
rrate
Annual return
Return as a percentage, such as 8 for 8%.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate the rule of 72 page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate The Rule Of 72, filed under Finance. Every number the guide produces comes from substituting into this one line.