Savings Goal Calculator

Intro

Use this savings goal calculator to estimate the monthly amount needed to reach a target by a chosen deadline. Enter the target, current savings, a positive number of whole months and an optional annual interest rate.

What this calculator does

The result is the estimated monthly contribution, with a chart comparing the projected balance with your goal. It assumes equal deposits at the end of each month, after that month’s interest has been added. It does not ask for your budget or check what you can afford.

How it works

Without interest, divide the remaining target by the number of months:

Monthly saving = max(0, goal - current savings) / months

With interest, let G be the goal, C the current savings, n the number of months, and r the annual percentage divided by 100 and then by 12. The end-of-month contribution is:

Monthly saving = max(0, (G - C × (1 + r)^n) × r / ((1 + r)^n - 1))

Current savings earn interest throughout the term. Each deposit starts earning in the following month. The model projects the next balance as previous balance × (1 + r) + monthly saving.

Example calculation

The worked examples on this page use US dollars (USD). Choosing UK - GBP changes the calculator's currency labels; it does not convert your entries or these examples.

Use a $10,000 goal, $1,500 current savings and a 24-month deadline. The interest rate in the second case is a hypothetical constant rate, not a current account offer or a forecast.

At 3%, the current $1,500 grows to approximately $1,592.64. The remaining future value comes from the monthly deposits and their interest. Using the unrounded monthly contribution, new deposits total approximately $8,168.17 and total interest is $331.83, giving $1,500 + $8,168.17 + $331.83 = $10,000.00 after rounding.

The displayed monthly contribution is rounded to cents; the chart uses the unrounded calculated amount. Saving the displayed amount can finish a few cents above or below the target, before account-specific interest and rounding differences.

Deposit timing

This calculator always uses end-of-month deposits and has no timing selector. For comparison only, the 3% example would require about $339.49 per month if every deposit were made at the beginning of the month instead: divide the unrounded end-month contribution by (1 + 0.03 / 12).

For the stated 3% inputs, this page returns $340.34 using its end-of-month assumption. Use the Compound Interest Calculator and its Timing control to model a beginning-of-period schedule.

Already reached or unattainable targets

If current savings already meet or exceed the goal, the required monthly contribution is $0.00. It can also be zero when projected interest alone is enough: $9,500 at 3% for 24 months grows to approximately $10,086.69 under this model, exceeding a $10,000 target without new deposits.

A deadline of 0 months is invalid; the calculator cannot grow a shortfall instantly. Negative goals, current balances and rates are also rejected. For a valid positive deadline, it calculates the contribution needed rather than deciding whether your target is affordable.

For example, with the $10,000 target, $1,500 start, 24 months and 0% interest, an affordable contribution of only $200 per month would produce $1,500 + $200 × 24 = $6,300, leaving a $3,700 shortfall. The calculator has no affordable-payment input and would still report the required $354.17. A plan needs a contribution, target and deadline that fit together.

How to use the result

Compare the required amount with your own budget. Recalculate when the target, deadline or account rate changes. Enter only savings available for this target, rather than money allocated to other commitments.

For the relationship between contributions, time and compounding, see Investor.gov’s compound interest calculator. The calculations on this page use the specific monthly assumptions explained above.

Assumptions and limitations

• Interest stays constant and is modeled as the entered annual percentage divided by 12, compounded monthly. This is not a conversion from AER or APY, which already includes compounding.
• Equal deposits arrive at month end. There are no missed deposits, withdrawals, changing contributions or exact calendar dates.
• Taxes, fees, inflation and account restrictions are excluded. A nominal cash target does not preserve a particular amount of purchasing power.
• The calculation uses full precision and rounds the displayed monthly amount. An actual account’s interest and cent-rounding rules can differ.
• The model accepts a non-negative goal, current balance and rate, and requires a positive deadline. It does not support negative rates or borrowing to meet a goal.
• This is an educational estimate, not a guarantee of interest, an assessment of affordability or financial advice.

How we explain formulas, assumptions and sources