Rule of 72 Calculator
The Rule of 72 is the quickest way to see how long it takes for money to double. Divide 72 by your annual return rate and you get the number of years. At 6 percent, money doubles in 12 years. At 9 percent, it doubles in 8. Use it to compare savings accounts, investment options, or how fast debt grows against you.
Your money doubles in
10.3
years
$10,000 → $20,000
How it works: Divide 72 by your interest rate. At 7%, money doubles every ~10.3 years.
10 yrs
$20K
vs $11K @ 1%
20 yrs
$39K
vs $12K @ 1%
30 yrs
$76K
vs $13K @ 1%
40 yrs
$150K
vs $15K @ 1%
50 yrs
$295K
vs $16K @ 1%
60 yrs
$579K
vs $18K @ 1%
Why 1%? Most checking and savings accounts pay around 1% or less. The line under each cell shows what the same dollars would be worth there.