THE NUMORIX GUIDE
How to use the Savings Goal Calculator
Last reviewed September 14, 2026
What this calculator does
The engine converts the annual rate to a monthly rate, then repeats: interest = opening balance x monthly rate; balance = opening balance + interest + monthly contribution.
Formula and method
The engine converts the annual rate to a monthly rate, then repeats: interest = opening balance x monthly rate; balance = opening balance + interest + monthly contribution. It stops when balance reaches the goal or after 600 months, while totalDeposited starts at current savings and totalInterest accumulates each month's interest.
Variables and inputs
Enter a positive savings goal, current savings, monthly contribution, and annual interest rate as a percent. The result reports months, a years display, total deposited, total interest, and a schedule when the schedule is no longer than 36 rows.
Worked example
With a $10,000 goal, $0 current savings, $200 monthly deposits, and 5% annual interest, the engine reaches the goal after 46 months. The ending balance is about $10,117.65, total deposits are $9,200, and modeled interest is $917.65.
How to interpret the result
Months to goal is the first simulated month after interest and the deposit are added. The result shows how contributions and return combine, but it does not promise that an account will earn the stated rate or that a goal is affordable in the household budget.
Common mistakes to avoid
Enter a monthly contribution, not an annual contribution divided informally. Keep the annual rate as a percent. If current savings already exceed the goal, the engine returns zero months; do not read that as a new savings plan.
Assumptions and limitations
The schedule uses a constant monthly rate and deposits after that month's interest. It ignores fees, taxes, changing yields, inflation, withdrawals, contribution timing choices, and account limits. If the goal is not reached within 600 months, the route returns the cap without a separate not-reached status.