Savings Goal Calculator
“Save $20,000” is a wish. “Put aside $523.81 a month for three years” is a plan. That is the whole job of this calculator: it takes the goal, the deadline, and whatever you have already saved, and works out the monthly habit that gets you there, with interest doing a small part of the work along the way.
Enter your numbers
Result
Enter your target, deadline, starting balance, and rate below.
Three levers, and one that isn’t
The monthly deposit is the headline: the amount to move into savings each payday. Total deposits show what comes out of your pocket. The interest figure shows what the account contributes.
If the monthly deposit looks too high, you have three honest levers: a longer deadline, a lower target, or a bigger starting balance. Raising the rate is not a lever you control, so don’t plan around a rate you can’t actually get.
The fine print matters too. The rate is assumed fixed, but savings rates move, and if yours falls, the deposit needed rises. Deposits are assumed to arrive at month end and start earning interest the following month. Taking money out mid-plan breaks the math and the habit. Taxes on interest and account fees are not included. And the target is in future dollars; for a goal years away, prices may rise.
Working backwards from the target
With a monthly rate and no starting balance, the deposit is:
Monthly deposit = Target × r ÷ ((1 + r)n − 1)
r is the monthly interest rate, yearly rate ÷ 12. n is the number of months until the deadline.
If you already have savings, that balance grows on its own and covers part of the target, so the deposit comes down. With a starting balance P, the calculator uses: Monthly deposit = (Target − P × (1 + r)n) × r ÷ ((1 + r)n − 1). If the rate is zero, it is simply the target divided by the number of months, no interest to help.
$20,000 in four years
Target $20,000, deadline 4 years (48 months), starting balance $0, savings rate 4% per year.
| Step | The math |
|---|---|
| Monthly rate | r = 0.04 ÷ 12 = 0.00333333 |
| Months | n = 48 |
| Growth factor | (1 + 0.00333333)48 = 1.173199 |
| Monthly deposit | $20,000 × 0.00333333 ÷ (1.173199 − 1) = $20,000 × 0.00333333 ÷ 0.173199 = $384.91 |
| Total you put in | $384.91 × 48 = $18,475.89 |
| Interest earned | $20,000 − $18,475.89 = $1,524.11 |
All figures rounded to the nearest cent. Interest covers $1,524.11 of the goal, so you deposit less than $20,000 yourself. With no interest at all, the deposit would be $20,000 ÷ 48 = $416.67 a month, about $32 more.
What if you start with $5,000?
$5,000 in 2 years at 3%: $202.41 a month.
$50,000 in 10 years at 5%: $321.99 a month.
Starting with $5,000 toward a $20,000 goal in 4 years at 4%: the $5,000 grows to $5,865.99 on its own, so the monthly deposit drops to $272.02. Money you already have is worth more than money you will save later.
Four fair questions
What if I miss a month?
One missed month is not a disaster, but the money does not catch up on its own. Re-run the calculator with the new remaining balance and the new deadline to get the corrected monthly amount, and carry on. The plan still works, it just needs the new number.
What if I already have some savings?
Enter it as the starting balance. It earns interest for the whole period, so it covers more of the target than the same amount saved later. In the example above, starting with $5,000 cut the monthly deposit from $384.91 to $272.02.
What if my savings account pays no interest?
Then the math is simple division: target divided by months. For $20,000 over 48 months, that is $416.67 a month. Even a modest rate helps, at 4%, the same goal costs $384.91 a month.
How much should I save each month?
It depends on the target, the deadline, and what you already have. This calculator gives you the exact number for your situation instead of a rule of thumb. If the number does not fit your budget, extend the deadline or lower the target, both are better than saving an amount you will abandon after two months.
More tools for the plan
- Compound Interest Calculator, see how savings grow once the habit is running
- Retirement Calculator, the same idea over a working lifetime
- Simple Interest Calculator, interest without compounding, for comparison
- Percentage Calculator, what share of your pay the deposit takes
- Mortgage Calculator, saving for a down payment is the most common goal
- Compound Interest Formula, the math behind the plan
- All Finance Calculators · All Calculators
General information and planning only. Not financial, investment, tax, or legal advice. Rates, taxes, and fees vary, and no result here promises a future balance, so check with a qualified professional before making financial decisions.
No external source needed here, the formula is standard arithmetic.