How do I calculate how much to save each month for a goal?

Subtract the future value of your current savings from your goal, then divide by the annuity factor ((1+r)^n - 1)/r, where r is the monthly rate and n the number of months. This calculator does exactly that and handles the zero-interest and goal-already-reached cases for you.

Does the calculator deposit at the start or end of each month?

Deposits are end-of-month (an ordinary annuity), the more conservative convention. If you deposit at the start of each month, divide the result by (1+r): on the default example $1,198.77 becomes $1,191.82.

How do I adjust my goal for inflation?

If your goal is stated in today's money, multiply it by (1 + inflation)^years before calculating. A $100,000 goal in today's money with 3% inflation over 5 years becomes a nominal target of $115,927, raising the required deposit from $1,198.77 to $1,421.25 per month.

What return rate should I use?

Match the rate to where the money will actually sit: roughly your savings-account or CD rate for near-term goals (1-3 years), and a conservative portfolio return for long-term goals (5+ years). Lower assumed rates mean a higher required deposit, which is the safer planning error.

Savings Goal Calculator – Monthly Amount Needed

Work backwards from your goal: the exact monthly deposit that reaches it.

Formulas:

Required monthly deposit: PMT = (FV − PV × (1 + r)ⁿ) / (((1 + r)ⁿ − 1) / r) where r = annualRate / 12, n = years × 12.
When the rate is 0%: PMT = (FV − PV) / n.
Goal in today's money: FV_nominal = FV_today × (1 + i)^years.

How the reverse savings calculation works

Working backwards from the goal

Most compound interest calculators run forwards: deposit X per month, end up with Y. Real financial planning usually runs the other way — you know the goal (a house down payment, an emergency fund, a wedding) and the deadline, and the missing number is the monthly deposit. This calculator inverts the future-value formula algebraically, so the answer is exact rather than trial-and-error.

What your current savings contribute

Your current savings are not subtracted from the goal one-for-one — they compound. $10,000 today at 7% for 5 years grows to about $14,176 by itself, so on the default example you only need to close a gap of roughly $85,824 with new deposits, not $90,000. That is why the required monthly deposit is lower than a naive division would suggest.

End-of-month deposits

The formula assumes each deposit lands at the end of the month (an ordinary annuity) — the conservative convention. If you save at the start of each month, divide the result by (1 + r): on the worked example below, $1,198.77 becomes $1,191.82.

Why the zero-interest case matters

When the rate is 0% (or you keep the money in a non-interest account), the annuity factor degenerates into a plain count of months and the formula becomes simple division. The calculator applies that limit automatically — no division-by-zero, no wrong answers.

Worked examples

Example 1: $100,000 in 5 years with $10,000 saved at 7%

Enter goal = 100000, currentSavings = 10000, annualRate = 7, years = 5. Result: deposit $1,198.77 per month. You deposit $81,926 in total; the remaining $18,074 of the goal is earned as interest.

Example 2: Same goal with a 0% account

Same inputs but annualRate = 0. Without compounding the entire gap is covered by deposits alone: $1,500.00 per month ((100,000 − 10,000) / 60). The difference — about $301 per month — is what earning 7% is worth here.

Example 3: Adjusting the goal for 3% inflation

If $100,000 is stated in today's money and inflation averages 3%, the nominal target is 100,000 × 1.03⁵ = $115,927. Enter goal = 115927 with the other inputs unchanged: the required deposit rises to $1,421.25 per month.

Related tools

The Savings Goal Calculator answers "how much must I save?". The natural follow-ups:

"What will I have if I save $X per month?" — that is the forward direction: use the Compound Interest Calculator.
"What if I put that money against my mortgage instead?" — compare with the Early Mortgage Payoff Calculator: paying down a 6% loan is a guaranteed 6% return.
"How do irregular cash flows fit in?" — for projects with mixed inflows and outflows, use the NPV / IRR Calculator.

Frequently asked questions

What if my current savings already reach the goal?

The required deposit becomes $0. When the compounded growth of your starting balance meets or exceeds the goal within the time frame, no new deposits are needed — the calculator tells you the goal is already covered.

Start-of-month or end-of-month deposits?

The result assumes end-of-month deposits (an ordinary annuity). If you deposit at the start of each month, divide by (1 + r) — on the default example $1,198.77 becomes $1,191.82.

How do I account for inflation?

Multiply a today's-money goal by (1 + inflation)^years before entering it. A $100,000 goal with 3% inflation over 5 years becomes a $115,927 target, which raises the required deposit from $1,198.77 to $1,421.25 per month.

What return rate should I assume?

Match the rate to where the money will sit: your actual savings-account or CD rate for near-term goals, a conservative portfolio return for horizons beyond five years. Underestimating the rate makes the required deposit higher — the safer planning mistake.

Is this the same as a sinking fund?

Yes, conceptually. A sinking fund is exactly this: a target amount, a deadline, and the periodic payment that bridges the gap. The math here is the standard sinking-fund formula with monthly compounding.