Saving
High-yield savings calculator
Enter an APY, your starting deposit and monthly deposits to project the balance and the extra interest compared with a low-rate baseline account.
Some inputs need attention. The results below are from your last valid entries.
Assumptions
Assumes the APY never changes, which is unlikely for a variable-rate savings account. Interest is generally taxable as ordinary income; taxes are not included.
High-yield vs baseline balance
| Year | Deposited | Interest (high-yield) | Baseline balance |
|---|---|---|---|
| 1 | $13,000 | $454.61 | $13,057 |
| 2 | $16,000 | $1,047 | $16,129 |
| 3 | $19,000 | $1,784 | $19,217 |
| 4 | $22,000 | $2,670 | $22,319 |
| 5 | $25,000 | $3,711 | $25,438 |
What APY means here
APY (annual percentage yield) is the effective yearly return after compounding. A 4.00% APY means $1,000 grows to $1,040 over a year if left untouched, regardless of whether the bank credits interest daily or monthly. That is different from APR or a “nominal” rate, so enter the APY your bank advertises, not the interest rate.
Methodology
Because APY is already effective, the monthly growth factor is (1 + APY)^(1/12). Each month the balance is multiplied by that factor and your deposit is added at month end, giving FV = P·g^n + D·(g^n − 1)/(g − 1) with g the monthly factor. The same deposits are run at the baseline APY to show what a low-rate account would have paid, and the difference is the extra interest.
Making sense of the comparison
The gap is largest when balances are big and the time is long. On a small emergency cushion the difference may be a few dozen dollars a year, which can still be worth an afternoon of switching. Remember that high-yield rates are variable, often move with interest rates set by the Federal Reserve, and may fall. Run a lower APY to see a cautious case.
Where this fits
- Choosing where to park cash? Read our high-yield savings guide.
- Set the target first with the emergency fund calculator, then work out timing with the savings goal calculator.
- Money you will not need for many years may suit investing; compare with the compound interest calculator.
Frequently asked questions
Is a high-yield savings account safe?
Accounts at FDIC-insured banks (or NCUA-insured credit unions) are insured up to applicable limits per depositor, per institution and ownership category. Confirm the institution is insured and check the current coverage limits.
Will my rate stay the same?
Probably not. Savings APYs are variable and the bank can change them at any time. This calculator holds the rate constant, so treat the result as an illustration.
Is the interest taxed?
Interest is generally taxable as ordinary income for the year it is earned. This calculator shows pre-tax figures.
Why compare with a 0.5% baseline?
It approximates what some traditional accounts pay, so the difference shows what a rate shopper could gain. You can change the baseline to your own bank's APY.
This calculator is for education and illustration. It does not account for taxes, fees or your personal situation unless stated, and is not financial advice.
Comparing where to open an account? See our providers to compare.
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