Investment Calculator
Project your investment's growth year by year, or find the monthly contribution needed to hit a savings goal.
How to use Investment Calculator
- Choose 'Project growth' to see how your investment grows over time, or 'Reach a goal' to work backward from a target amount.
- In Project growth: enter your starting balance, monthly contribution, expected annual return, and time horizon — see the final value and a year-by-year table.
- In Reach a goal: enter your target amount, current savings, expected return, and timeframe — see the monthly contribution required.
About this tool
The Investment Calculator has two modes. 'Project growth' shows a year-by-year breakdown of how a starting balance plus monthly contributions grows at a given return rate — not just the final number, but the trajectory. 'Reach a goal' works backward: tell it your target amount, timeframe, and expected return, and it solves for the monthly contribution required to get there. All calculations run instantly in your browser — nothing is uploaded or sent to a server.
Frequently Asked Questions
What return rate should I use?
This is your choice to research — historical long-term stock market averages are often cited around 7-10% before inflation, but actual returns vary significantly by investment type and time period. This calculator projects a fixed rate; it doesn't predict future returns.
Does this account for inflation or taxes?
No — this shows nominal growth only. To estimate real (inflation-adjusted) growth, use a lower return rate that reflects your expected return minus inflation.
How is the required monthly contribution calculated in 'Reach a goal' mode?
It rearranges the future-value-of-an-annuity formula to solve for the payment amount, given your goal, current savings, rate, and time — the exact inverse of the growth projection calculation.