Rule of 72 Calculator
Quickly estimate the number of years required to double your money at a given fixed rate of return.
At 8% annual return, your investment will double approximately every 9 years.
Burnjet provides calculators and educational tools for general informational purposes only. Results depend strictly on the mathematical assumptions you enter and do not guarantee future financial, stock market, or tax outcomes. This tool does not provide financial, investment, legal, or professional tax advice.
Quick Reference & Instructions
Simple steps, pro tips, and execution details
Enter Your Numbers
Type in your initial amounts, interest rates, or investment duration below.
Live Instant Calculation
Watch the charts, returns, and breakdown tables update immediately as you tweak numbers.
Copy or Plan Next Steps
Copy summary results or use the visual breakdown to make informed financial decisions.
How It Works
Divides 72 by your annual interest rate to provide a reliable estimate of investment doubling time.
Formula & Logic
Years to Double ≈ 72 / Rate of Return (%)Frequently Asked Questions
Common questions about calculations, assumptions, and edge cases.
It's a mental-math approximation, most accurate for annual rates roughly between 6% and 10% — at very high or very low rates the estimate drifts further from the exact compound-interest answer.