Grow
Savings goal calculator
Either ask what to save each month to hit a target on time, or ask how long a fixed deposit takes. Deposits are treated as end-of-month.
Results
- Monthly deposit to set aside
- $360.42
- Projected balance
- $30,000.46
- Contributed by you
- $26,625.20
- Interest earned
- $3,375.26
- Year 1$9,608.93
- Year 2$14,405.63
- Year 3$19,397.76
- Year 4$24,593.27
- Year 5$30,000.46
How to use this page
- Replace the sample numbers with your own. Nothing is sent to a server.
- Read the result. It changes as you type.
- Open the formula if you want to recompute the result by hand.
- Copy the result if you want to keep it. The numbers you type stay in this browser and are not added to the address.
Formula
With monthly rate r and n months, target = current × (1+r)^n + deposit × [((1+r)^n − 1) ÷ r]. Solving for the deposit gives deposit = (target − current × (1+r)^n) × r ÷ ((1+r)^n − 1). The page rounds that deposit up to the next cent, yen, or won so the plan does not fall short by a rounding unit. Solving for time walks month by month until the balance reaches the target.
Which question you are asking
Find the deposit when the date is fixed: a trip, a tuition bill, a down payment on a known month. Find the time when the deposit is fixed: you already know what you can spare each month.
If the money already saved can reach the target by itself, the deposit is shown as zero. Leaving the money invested may still grow it past the target. That growth is in the projected balance, and it assumes the rate you typed stays put.
Why the deposit may be a unit higher than the pure formula
A pure formula can ask for 83.333 dollars a month. You cannot transfer a third of a cent. Rounding up means the projected balance can finish slightly above the goal. That is intentional.
The rate is a nominal annual rate compounded monthly, same as the compound-interest page. A goal that is only a cash envelope with no interest should use a 0% rate. Do not invent a market return for money that will sit in a drawer.
Easy mistakes
- Comparing a 0% envelope with a 7% invested account as if the risk were the same.
- Forgetting that a target in today's prices moves. Pair this page with the inflation calculator if the purchase is years away.
- Entering the target as the extra amount you still need when you have also filled in the current balance. The target is the full balance you want, not the gap.
Questions
What if I will start the deposit next year?
Use the compound-interest page for the waiting year with a zero deposit, then use that future balance as the current savings here.
Does a zero result mean I should stop saving?
It means this particular target does not require a new deposit. A later target, an emergency buffer, or a lower real rate might.
Why did the time solver stop at 100 years?
At 0%, monthly deposits still increase the balance. The calculation stops if interest and deposits do not bring the balance to the goal within 100 years.
Related tools
These figures are estimates you can recompute from the formula on the page. They are not a lender quote, a tax bill, a payroll statement, or financial advice.