Savings Calculator

A savings account grows two ways: the interest your balance earns, and the money you add to it yourself. This calculator projects both together — starting from an optional initial deposit, adding a fixed contribution every month, and letting the whole balance earn interest that compounds monthly, the same way most savings accounts actually work.

You only need to fill in a deposit or a monthly contribution — not necessarily both. Enter the annual interest rate as an APY (Annual Percentage Yield), since that's how banks typically advertise savings rates, and it already reflects the effect of compounding rather than a raw, uncompounded rate.

The result is a projection, not a guarantee: it assumes your rate stays constant for the entire period, which real savings APYs rarely do — banks adjust rates over time based on broader interest-rate conditions. It also doesn't account for taxes on the interest you earn or for inflation eroding the real value of that balance. Use it to compare scenarios (a higher contribution, a longer timeline, a better rate) rather than as a promised future balance.

A worked example

Say you start with a $1,000 initial deposit, add $200 every month, and earn a 4% APY for 10 years. Plugging into the formula gives a final balance of $30,940.79. Of that, $25,000 came directly from your own deposits and contributions ($1,000 + $200 × 120 months), and the remaining $5,940.79 is interest the account earned along the way — roughly 19% of the final balance came from interest alone, not from money you put in.

A common misconception

People often assume any two rates with the same number mean the same thing, but the number that matters for comparing accounts is APY specifically, not a plain, uncompounded interest rate. Per the Truth in Savings Act (implemented through Regulation DD, now maintained by the CFPB), banks are required to disclose the APY precisely because it already factors in compounding, making it the only number that lets you compare two accounts on equal footing — a bank quoting a lower nominal rate with more frequent compounding can sometimes out-earn a higher rate compounded less often.

Where this projection runs into limits

This tool assumes your rate holds perfectly steady for the entire time horizon, but real savings APYs move with broader interest-rate conditions — a bank can and does change its rate with little notice, so a 10-year projection at today's rate is a snapshot, not a forecast. It also doesn't subtract taxes owed on the interest you earn (interest income is generally taxable) or account for inflation, which erodes what that final balance can actually buy by the time you reach it — both mean the real, spendable value of the projected balance is lower than the raw number shown.

How to use this result

Use the final-balance and interest-earned breakdown to test how sensitive your goal is to each input — a higher monthly contribution, a longer timeline, or a better rate. Because a meaningful share of long-term growth comes from interest-on-interest rather than your own contributions (as in the worked example above), starting sooner, even with a smaller amount, is usually more powerful than waiting to contribute more later. If this balance is meant to be an emergency fund specifically, the CFPB's general guidance is to target roughly three to six months of essential expenses — housing, groceries, utilities, transportation, and routine medical costs — as a savings goal, though the right amount depends on your own income stability and expenses.

Savings vs. investing

This calculator models a savings-account-style APY, which is why its rate is capped at a realistic bank-savings range: savings accounts prioritize safety and liquidity over growth, typically holding your balance in cash-equivalent, FDIC-insured deposits. Investment Calculator models a different kind of growth — money placed in securities like stocks or funds, which can earn a higher expected return over the long run but carries real risk of loss that a savings account doesn't. Which is appropriate depends on the money's purpose: savings for a near-term goal or emergency fund generally belongs somewhere safe and liquid, while money with a longer time horizon can typically afford to take on the added risk investing carries.