Savings Calculator

APY is the effective return over one year, including compounding. This calculator converts APY to an equivalent monthly rate and assumes deposits at the end of each month, a constant APY, and no taxes or fees.

i = (1 + APY/100)^(1/12) − 1; n = 12t; FV = P(1 + i)^n + c · [((1 + i)^n − 1) / i]. At 0% APY, FV = P + cn.

$5,000 plus $200 deposited at the end of each month at 4.5% APY for 10 years grows to $37,859.98: $29,000 deposited and $8,859.98 interest.

• Plan an emergency fund of 3–6 months of expenses.
• Save toward a down payment or vacation.
• Compare high-yield savings accounts.

1. Enter the starting balance and the monthly contribution as separate amounts.
2. Use APY as an effective annual yield, then enter the saving period in years.
3. Compare the ending balance with total deposits so that growth is not confused with your own contributions.

With $1,000 initially, no monthly contribution, 10% APY, and 1 year, the ending balance is $1,100 before fees or tax. For monthly calculation the equivalent rate is (1.10)^(1/12) − 1, not simply 10% divided by 12.

• The illustration holds APY constant and does not include fees, tax, inflation, or changes in account terms.
• Monthly contributions follow the timing stated in the formula; deposits made at different times can produce different results.