Compound interest calculator
See how a starting balance and steady monthly contributions grow over time when your returns compound. Adjust the numbers to your own plan.
After 30 years at 7% a year, compounded monthly.
Your starting balance plus every contribution
Growth on top of what you contributed
Estimates only, not financial advice. Assumes a constant annual return compounded monthly with level monthly contributions. Real returns vary and are not guaranteed.
Why compounding matters
The earlier you start and the longer you stay invested, the more of your ending balance comes from growth rather than from what you put in. Small changes to your monthly contribution or your time horizon can move the final number by a lot, which is why a plan that keeps you invested is worth more than picking the perfect year to start.
The same math cuts the other way for fees. A percentage-of-assets advisor takes a slice of this growing balance every year. See how that compounds against a flat fee with the AUM vs flat-fee calculator , or book a free consultation .