Savings goal

Savings goal: the basics

Estimate the equal monthly saving needed to reach a target, allowing an existing balance to grow toward it.

How to use the inputs

• Savings target: Enter the total amount you want at the end, not just the amount still missing.
• Already saved: Enter the money already saved and available at the start.
• Annual interest rate: Enter an assumed annual interest percentage from 0 to 50. Actual future rates may differ.
• Time to reach goal: Enter the whole-year time available, from 1 to 60.

Change an input to update the results. Add up to four scenarios to compare separate assumptions; reset affects only the selected scenario.

Understanding the results

• Monthly savings needed is the regular deposit required under your assumptions; it cannot be negative.
• Savings target and already saved repeat your inputs. The chart combines growth of the existing balance with the new month-end deposits.

The formula, in words

Monthly saving M = max(0, (T − P × (1 + r) raised to n) ÷ F), where F = ((1 + r) raised to n − 1) ÷ r.

T is the target, P is already saved, R is the annual percentage entered, r = R ÷ 1200 is the monthly decimal rate, Y is years, and n = 12 × Y. F is the future value of depositing one currency unit each month. max(0, …) chooses zero if the computed deposit is negative.

At 0%, M = max(0, (T − P) ÷ n). Ending value = P × (1 + r) raised to n + M × F; at 0%, it is P + M × n.

Assumptions and limits

• Existing savings are present at the start; new equal deposits arrive at month-end. Interest compounds monthly at a constant assumed annual percentage divided by 1200.
• There are no withdrawals, taxes, fees or inflation adjustments. The chart uses the unrounded monthly saving, even though the screen displays whole currency units.
• If existing savings alone are projected to reach the goal, the required deposit is zero. The chart may then end above the target; it is not capped at the goal.

Currency results display whole units; other numbers show at most one decimal place. Calculations keep full precision unless whole units must be rounded up for break-even. Rounded figures may not add up exactly.

Examples below use USD and local number formatting. Country selection changes currency labels, formatting and terminology; it does not convert money or automatically apply local tax or lender rules.

Worked example

This fixed example uses the calculator’s default inputs; it does not change when you edit a scenario. Any example interest or return rate is an assumption, not a guaranteed outcome.

Savings target

USD 50,000

Already saved

USD 5,000

Annual interest rate

4%

Time to reach goal

5 years

There are 60 month-end deposits. First grow USD 5,000 for 60 months at r = 4 ÷ 1200. Subtract that future balance from USD 50,000, then divide by F for 60 deposits. The required monthly amount displays as USD 662; the unrounded amount reaches the target in this model.

Monthly savings needed

USD 662

Savings target

USD 50,000

Already saved

USD 5,000

Common questions