Rule of 72 Calculator
Estimate how long it takes to double your money.
Input
%
Quick Select
Formula
72 ÷ 7 = 10.3 yr
Years to Double
10.3yr
Investment doubles by 2036
How it Works
Divide 72 by your annual return rate to estimate the years needed to double your investment. It works in reverse too: divide 72 by your target years to find the required annual rate.
Doubling Timeline
2x
10.3yr
2036
4x
20.6yr
2047
8x
30.9yr
2057
16x
41.1yr
2067
@ 7% annual return
Asset Comparison
AssetTypical ReturnDoubles In
Savings~1%72 yr
Bonds~4%18 yr
Real Estate~7%10.3 yr
S&P 500~10%7.2 yr
Growth Stocks~15%4.8 yr
Inflation Impact
The Rule of 72 also reveals how fast inflation erodes purchasing power. At 3% annual inflation, prices double in just 24 years — meaning your money's purchasing power is cut in half.
2% inflation
halves in 36 yr
3% inflation
halves in 24 yr
5% inflation
halves in 14.4 yr
8% inflation
halves in 9 yr
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