A quick mental-math shortcut for how fast money doubles at a given return.
Your return
1%20%
$
Doubling time
Your money doubles in
,
The Rule of 72 estimates doubling time as 72 ÷ rate. It's an approximation that's most accurate for rates around 6-10%; the exact figure uses logarithms. The Rule of 114 estimates tripling, and 144 quadrupling.