Savings Goal Calculator

Because more of your Savings Goal gets covered by growth on money already in the account rather than by new contributions. At a higher rate, both your Current Savings and every monthly deposit compound faster, so you need to contribute less out of pocket each month to land on the same target -- the account is doing more of the work for you. This is exactly why Interest Earned rises alongside interest rate even though the goal amount never changes.

Extending the Timeframe lowers the required monthly (and weekly) deposit, since the same total gap between Current Savings and the Savings Goal gets spread across more contributions, each of which also has more time to compound. The tradeoff is that a longer timeframe delays reaching the goal -- this calculator optimizes for the smallest monthly commitment to hit a fixed end date, not for the fastest path to the goal.

Weekly Deposit is the Monthly Deposit Needed multiplied by 12 (to annualize it) and then divided by 52 -- it is a unit conversion for budgeting convenience, not a separately compounded weekly calculation. If you actually deposit weekly rather than monthly, your real balance will compound slightly faster than this model assumes, since each of the 52 smaller deposits starts earning interest a little sooner than one lump monthly deposit would.

Not quite -- Current Savings reduces the required monthly deposit by more than a simple dollar-for-dollar amount, because that starting balance also compounds for the full Timeframe before the goal date arrives. The relationship is a constant amount per dollar of starting balance, not an accelerating one: at the default 4.5% rate over 24 months, every extra $1,000 of Current Savings lowers Monthly Deposit Needed by about $43.65, all the way down until the required deposit reaches zero. Because that saving happens every month for two years, $1,000 of Current Savings ends up offsetting roughly $1,048 of total deposits over the full Timeframe -- more than dollar-for-dollar in total, just not at an accelerating rate along the way.