Double Your Money Calculator
See how many years it takes to double your money at any annual growth rate — or set your own target, like triple or 10x.
Enter your numbers
100% gain = double your money. Type any value of 100% or more, e.g. 150% = 2.5x.
The time to reach your target is the same for any amount — this only shows the money values.
- Rule of 72 estimate
- 9 years
- Target multiple
- 2x
- $10,000 becomes
- $20,000
Years to double at different rates
Click a rate to use it above.
Milestones at 8%
- 2x 9 years $20,000
- 3x 14 years 3 months $30,000
- 5x 20 years 11 months $50,000
- 10x 29 years 11 months $100,000
Good to know
These figures assume the same growth every year, with returns reinvested and no extra deposits or withdrawals. Real investments go up and down, and fees, taxes and inflation can make doubling take longer.
Growth path to $20,000
In plain terms
At 8% a year, $10,000 reaches $20,000 in about 9 years. You pass the target during year 10.
About the Double Your Money Calculator
The Double Your Money Calculator tells you how many years it takes for an investment to double at a steady annual growth rate (CAGR). Because returns compound — each year's growth is added to the amount that grows the next year — the time to double depends only on the rate, not on how much you start with.
The exact formula is Years = ln(Target multiple) ÷ ln(1 + Rate). For doubling, the target multiple is 2. You can also set any target of 100% gain or more — for example 200% (triple), 400% (5x) or 900% (10x). The calculator also shows the popular Rule of 72 shortcut, a comparison across common growth rates, and milestones for 2x, 3x, 5x and 10x.
How to Use the Double Your Money Calculator
- Enter an annual growth rate. Pick a quick rate like 7% or 10%, or type your own CAGR.
- Choose your target. Double (100% gain) is the default. Pick Triple, 4x, 5x or 10x, or type any gain of 100% or more.
- Add a starting amount (optional). Enter how much you invest to see what it grows to. This does not change the number of years.
- Read the result. See the exact time in years and months, the Rule of 72 estimate, and your ending amount.
- Compare rates. The comparison chart shows how long the same target takes at other rates. Click any row to use that rate.
Frequently Asked Questions
How long does it take to double my money?
It depends on the annual growth rate. At 6% it takes about 11.9 years, at 8% about 9 years, at 10% about 7.3 years, and at 12% about 6.1 years. The amount you start with does not change the time.
What is the Rule of 72?
The Rule of 72 is a quick way to estimate doubling time: divide 72 by the annual rate. For example, 72 ÷ 8 = 9 years. It is most accurate for rates between about 6% and 10%. For other targets, this calculator scales the rule: Rule of 72 years × log₂(target multiple).
How do I calculate the time to triple or 10x my money?
Use Years = ln(multiple) ÷ ln(1 + rate). To triple at 10%, that is ln(3) ÷ ln(1.10) ≈ 11.5 years. To 10x at 10%, it is ln(10) ÷ ln(1.10) ≈ 24.2 years. Set the target growth to 200% or 900% above to see it instantly.
What does "target growth %" mean?
It is the total gain you want on top of your starting amount. 100% gain means your money doubles (2x), 200% means it triples (3x), and 150% means it grows 2.5x.
Does this include inflation, fees or taxes?
No. The result uses the rate you enter as-is. To see how long it takes to double your buying power, enter a real (after-inflation) rate — for example, a 9% return with 3% inflation is roughly a 6% real rate.
What growth rate do I need to double my money in a set number of years?
Divide 72 by the number of years for a quick estimate — doubling in 6 years needs about 12% a year. For an exact rate between any two values, use the CAGR Calculator.