How it works
The annual rate is divided by 12 and compounded monthly, with contributions added at the end of each month. Final value = initial × (1+r)^n + monthly × ((1+r)^n − 1) ÷ r.
Rule of 72
Divide 72 by the annual return (%) to estimate how many years it takes to double. At 8% that is about 9 years.
What to keep in mind
Stock returns vary widely from year to year, so a constant-rate projection is only a guide. Taxes, fees and inflation are ignored.