How much to save each month
Say what you want and when. We work out the monthly amount, and how much of it the return contributes instead of you.
Your figures
Result
- Per year
- $4,497
- Total you will put in
- $27,487
- What the return contributes
- $2,513
- Monthly amount with no return
- $416.67
- What the return saves you each month
- $41.89
Year by year
| Year | Contributed | Return | Total |
|---|---|---|---|
| 1 | $9,497 | $212 | $9,709 |
| 2 | $13,995 | $564 | $14,559 |
| 3 | $18,492 | $1,063 | $19,555 |
| 4 | $22,989 | $1,711 | $24,700 |
| 5 | $27,487 | $2,513 | $30,000 |
What we assume
- The return is effective annual and compounds monthly.
- Contributions are assumed to be made at the end of each month and to stay constant.
- No tax, fees or inflation are deducted. Over ten years or more, inflation matters: consider raising the goal accordingly.
- A constant return is a mathematical convenience, not a description of any real market.
How it is calculated
The goal has to be covered by two things: what your starting amount grows into, and what your monthly contributions grow into. Rearranging the compound interest formula for the monthly payment gives:
monthly = (goal - start x (1 + i)^n) x i / ((1 + i)^n - 1)
where i is the monthly rate and n the number of months.
The figure worth comparing
We show what you would have to save with no return at all, next to the real figure. The gap between them is what the market is doing on your behalf — and over short horizons it is almost nothing, which is the honest answer for a two-year goal.
An example
To reach 30,000 in 10 years starting from 5,000 at 5%, you need about 140 a month. With no return at all it would be 208: the growth is saving you roughly 68 every month.
Frequently asked questions
What return should I assume?
For a short horizon, close to zero: you should not take market risk with money you need in two years. For a long one, be conservative — an optimistic assumption today becomes a shortfall later.
Should I adjust the goal for inflation?
For anything over about five years, yes. 30,000 in ten years buys noticeably less than 30,000 today. Either raise the goal or subtract expected inflation from the return.
What if I cannot manage the monthly figure?
Extend the horizon before raising the assumed return. Time is the variable you actually control; the return is not.
Keep calculating
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Updated on 2026-08-26. Calculations run in your browser; nothing you type is sent to a server.