// RETURN TO DOUBLE
Return Required to Double Money Calculator
What annual return is needed to double your money in a chosen number of years?
// INPUTS
In how many years do you want to double?
// OUTPUT
REQUIRED ANNUAL RETURN
10.41%
RULE OF 72 ESTIMATE10.29%
// FORMULA
// FORMULA
r = 2 ^ (1 / Years) − 1
The result is the compounded annual rate that exactly doubles the amount.
// EXAMPLE
// WORKED OUT
To double in 7 years:
r = 2 ^ (1 / 7) − 1
= 1.1041 − 1
= 10.41% per year
Rule of 72: 72 / 7 ≈ 10.29%// WHAT THIS MEANS
This is the inverse of the doubling-time question. If you have a horizon in mind, the calculator tells you the rate you need. A 10-year horizon needs ~7.2% per year, a 5-year horizon needs ~14.9%, and a 3-year horizon needs ~26%. Use it to sanity-check ambitious return assumptions.
// FAQ
Is this what an investment 'should' deliver?+−
No — it tells you what is mathematically required. Whether any real investment can deliver that rate consistently is a different question entirely.
Why does the Rule of 72 give a slightly different number?+−
It is an approximation. For doubling-period questions in the 5–15% range it is very close, but the exact formula is always correct.
// RELATED CALCULATORS
// COMPOUNDING
Doubling Time Calculator
How long money takes to double at a given rate.
// COMPOUNDING
Rule of 72 Calculator
Quick doubling-time approximation.
// RETURN MATH
CAGR Calculator
Annualized growth rate between two values.
// COMPOUNDING
Investment Growth Calculator
Future value of a lumpsum at a chosen rate.