How to use it
- Choose what to solve for: the ending balance by default, or the deposit, return, years or starting amount (then enter a target).
- Enter amounts, rate, years and compounding; More options adds yearly deposit increases and inflation.
- Read the result, the breakdown chart and the yearly schedule, and export CSV for further analysis.
CAGR vs average growth
Sales +100% one year and −50% the next average +25%, yet end where they started: CAGR is 0%. CAGR uses only the start and end, showing the steady yearly rate that gets you there, which makes periods and projects comparable.
Rule of 72: years to double
Divide 72 by the annual growth rate in percent to estimate the years to double. It is most accurate between 6% and 10%.
| Annual rate | Rule of 72 | Exact years |
|---|---|---|
| 2% | 36.0 | 35.00 |
| 4% | 18.0 | 17.67 |
| 6% | 12.0 | 11.90 |
| 8% | 9.0 | 9.01 |
| 10% | 7.2 | 7.27 |
| 12% | 6.0 | 6.12 |
| 15% | 4.8 | 4.96 |
| 20% | 3.6 | 3.80 |
Frequently asked questions
How is CAGR calculated?
CAGR = (end ÷ start)^(1 ÷ years) − 1. Revenue growing from 1.0M to 1.8M in 4 years gives 1.8^(1/4) − 1 ≈ 15.83%. Both values must be above 0.
How accurate are the results?
Formulas are exact and compounding is simulated period by period, shown to the cent. Real returns fluctuate and banks differ on day counts, tax and fees, so use the results for planning and comparison.