How this calculator works
The calculator first grows your existing savings to the target date, then finds the fixed monthly deposit that fills the remaining gap. If existing savings already meet the goal after growth, the required deposit is zero.
C = max(0, G − P(1 + r)ⁿ) × r / ((1 + r)ⁿ − 1)P = starting amount; C = monthly contribution; G = target; r = monthly rate; n = months; y = years, where applicable.
Example you can check
To reach $12,000 from $0 in two years with 0% interest, deposit $500 each month.
Assumptions & limitations
Interest compounds monthly using a constant nominal annual rate. Deposits occur at month-end. At 0% interest, the remaining gap is divided evenly across the months. No withdrawals, tax or account fees are included.
Common questions
Why is my required deposit zero?
Your current balance, with the selected interest rate, already reaches or exceeds the target.
What if rates change?
Recalculate with a lower rate for a more cautious savings scenario.
Further reading: investor.gov educational guide. Our formula conventions and examples are described above.