Rule of 72 at 7% Return: How Long to Double $10,000?
At a 7% annual return, $10,000 doubles in approximately 10.3 years according to the Rule of 72.
How to use this tool
- Enter annual return rate, starting amount and projection years in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your years to double (rule of 72) and the full breakdown beneath it.
The Rule of 72 shows that at 7% annual return, any amount of money doubles in roughly 10.3 years — a key concept in long-term investing.
Frequently asked questions
- How accurate is the Rule of 72?
- It's a good approximation for rates between 6% and 10%. For exact doubling time, use ln(2) / ln(1 + r) ≈ 0.693 / r.
- Does it work for debt too?
- Yes — at 18% APR your credit card debt doubles in roughly 4 years if you make no payments. The rule is a powerful reminder of compounding in reverse.