Using the Investment Calculator
Change one assumption at a time: the monthly contribution, the return or the number of years. This makes it easier to see which part of the plan is doing the work. A projection is a scenario, not a promise from a fund or market.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Starting balance
- 10000
- Monthly contribution
- 200
- Annual nominal return (%)
- 5
- Years
- 10
Example result
- Future balance
- 47,526.55
- Total contributions
- 34,000
- Growth
- 13,526.55
Method and assumptions
Monthly compounding with end-of-month contributions and a constant nominal annual rate. Taxes, fees and market fluctuations are excluded.
Separate contributions from growth
An ending balance can grow because you put more money in, because the assumed return is higher, or because the money has more time to compound. Those are different effects. Keep the contribution schedule consistent when comparing rates, and distinguish a mathematical projection from a return that is contractually guaranteed. Fees and taxes need their own assumptions.
Common question
Are contributions added at the start or end of the month?
At the end. A contribution made at the beginning of a month has an extra month to grow and would produce a slightly different result.
Guide updated .