Mental Model Calculator
Rule of 72 Calculator
Quickly estimate how many years it will take for your money to double at any given interest or return rate.
Input Rate
8%
Standard Asset Benchmarks:
Time to Double Money
~9.0 Years
Exact logarithmic calculation: 9.01 years
Doubles at
9.01 yrs
Exponential Doubling Milestones
1
$20,000
1x (2x Wealth)
9.0 yrs
from starting point
2
$40,000
2x (4x Wealth)
18.0 yrs
from starting point
3
$80,000
3x (8x Wealth)
27.0 yrs
from starting point
4
$160,000
4x (16x Wealth)
36.0 yrs
from starting point