Compound Interest Calculator
See how savings grow when interest earns interest. Watch how much of the final balance is your own contributions versus pure growth, and how time changes everything.
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How this is calculated
Growth is compounded monthly. Your starting amount grows on its own, and each monthly contribution is added and then compounds from that point on. In formula terms the final balance is the starting amount times (1 plus the monthly rate) to the power of the number of months, plus the future value of the stream of monthly contributions.
The monthly rate is your annual return divided by twelve. Contributions are treated as arriving at the end of each month, which is the standard, slightly conservative assumption.
Time versus contribution amount
The two levers under your results show why time is so powerful. Adding a few more years, or starting sooner, often does more than raising your monthly contribution, because every extra year gives the whole balance another round of compounding. Early money is the money that grows the most.
Next steps
Bremo is an independent Canadian personal finance resource, not an adviser. Investment returns are not guaranteed and vary year to year. This tool is a simplified model for general education, before inflation, fees and tax. Use a return you can justify.
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