Time to your goal
3 years, 6 months
42 monthly contributions
You contribute
$18,800
including your starting balance
Interest earned
$1,501
free money from compounding
Where the final balance comes from
The longer the goal, the larger the green slice — that is compounding doing the work for you.
Final balance
$20,301
target was $20,000
Monthly contribution
$400.00
× 42 months
How the Savings Goal Calculator Works
The method
Each month your balance earns one twelfth of the annual rate, then your contribution is added on top. The calculator steps forward month by month until the balance reaches your target. Stepping rather than solving a formula means compounding is handled exactly and awkward cases — a 0% rate, a goal already met — come out right instead of producing a divide-by-zero.
Why compounding matters more over time
Compound interest is interest earned on your interest. Each month's interest joins the balance, so the next month earns slightly more. Over a couple of years the effect is barely visible and your contributions do nearly all the work. Over a couple of decades it can rival or overtake them — which is why the split between your money and interest above is worth watching as you change the term.
Choosing a rate
Use what your account actually pays — for a savings account, the quoted APY. For long-term investing, 6-7% is a common assumption based on historical stock market averages, but that is an average across decades and not a promise for any single year. The result is in nominal terms, so for today's money subtract expected inflation from your rate.
Frequently asked questions
How is the time to reach a savings goal calculated?
Each month your balance earns interest at one twelfth of the annual rate, then your contribution is added. The calculator steps forward month by month until the balance reaches your target, which handles compounding exactly and copes with edge cases like a zero interest rate.
What is compound interest?
Compound interest is interest earned on your interest, not just on what you deposited. Because each month's interest joins the balance, the following month earns a little more. Over a long period this snowballs — it is why starting early matters more than contributing slightly more later.
What interest rate should I use?
Use the rate your account actually pays. For a savings account that is the quoted APY, often 0.5% to 5% depending on the account and the times. For long-term investment goals people often assume 6-7% as a historical stock market average, but that is an average across decades, not a guarantee for any given year.
Why does my goal say it can never be reached?
That happens when there is nothing to grow the balance: no monthly contribution and no interest, or a negative rate eroding it. With no money going in and no growth, the balance never rises, so the target is genuinely unreachable. Add a contribution or a positive rate.
Does this account for inflation?
No — the result is in nominal terms, so $50,000 in fifteen years will buy less than $50,000 does today. To think in today's money, use a real rate of return: subtract expected inflation from your rate. If you expect 7% growth and 3% inflation, enter roughly 4%.
Should I contribute more or invest at a higher rate?
For short goals, contributions dominate — there simply is not time for compounding to matter much. For long goals the rate matters increasingly, because interest compounds on interest. The comparison of what you contributed against what you earned in interest, shown alongside the result, makes the split clear for your particular numbers.