Use this free savings calculator to see how your money grows with compound interest. Enter a starting balance, a monthly contribution and your account’s APY to instantly see your future balance, total deposits and interest earned – with a year-by-year breakdown.
Year-by-year breakdown
| Year | Deposited | Interest | End balance |
|---|
Estimates only. Actual returns depend on your account’s APY, rate changes and deposit timing. Not financial advice.
How this savings calculator works
The calculator grows your balance month by month: it converts your APY into an exact equivalent monthly rate, applies that growth, then adds your monthly contribution. The formula is FV = P(1 + i)^N + PMT × [((1 + i)^N – 1) / i]. For our standards, see how we rate banks and apps, and you can cross-check the concept with the U.S. Securities and Exchange Commission.
Tips to grow your savings faster
- Pick a high-yield account. A few points of APY add up fast.
- Automate deposits. Regular contributions compound steadily.
- Start early. Time is the biggest driver of compounding.
- Reinvest interest. Leaving earnings in keeps the engine running.
How to use this savings calculator
Start by entering your current balance in the initial deposit field, then add the amount you can set aside each month. Type in the APY from your account – not the headline base rate – and choose how often interest compounds. Finally, set how many years you plan to save. The results update instantly: your projected balance, the total you will have deposited, and the interest your money earns on its own. Use the year-by-year breakdown to watch the balance accelerate as interest begins compounding on itself.
A real savings example
Suppose you open a high-yield savings account with $1,000 and add $200 every month at a 4% APY. After ten years you would have about $30,941 – and roughly $5,941 of that is pure interest you never had to work for. Raise the APY to 5%, or extend the horizon to fifteen years, and the interest portion grows even faster, because compounding rewards both higher rates and longer time. For free, unbiased guidance on saving and comparing accounts, see the U.S. Consumer Financial Protection Bureau.

Frequently asked questions
How is compound interest calculated?
Compound interest is calculated on both your deposit and the interest already earned. This tool converts your APY into an exact monthly rate, grows the balance each month, then adds your contribution.
What is the difference between APY and interest rate?
The interest rate is the base rate; APY includes the effect of compounding, so it reflects what you actually earn in a year. Compare accounts by APY and enter the APY here.
Does compounding frequency matter?
Yes, but less than the rate. Daily compounding earns slightly more than annual at the same nominal rate; for most savings accounts the gap is small.
How much will my savings grow?
For example, $1,000 plus $200 a month at a 4% APY grows to about $30,941 in 10 years, roughly $5,941 of it interest. Change any value to model your plan.
Is this savings calculator accurate?
The math uses the standard compound-interest formula with monthly contributions and is verified against known values. Results are reliable estimates.
