Future view
Savings growth
Projection using the selected rate, compounding frequency, balance, and monthly deposit.
Savings rate lab
APY Calculator
Turn a bank's stated rate into the yield you actually earn. Compare compounding schedules, project your balance, and see the dollar difference at a glance.
4 frequencies compared
Live savings projection
Exact APY conversion
Step 2 · Your rate snapshot
Formula
APY = (1 + r / n)n - 15.116%5-year projection
Same stated rate
Compounding comparison
The comparison holds the nominal rate constant. It does not imply that two real accounts offer the same stated rate or terms.
Rate ladder
APY and first-year interest
| Compounding | APY | Interest after one year | Ending balance |
|---|
Worked examples
Popular APY calculations
These examples use a nominal annual rate and monthly compounding. Actual account disclosures may already state APY, making conversion unnecessary.
3.75% interest rate
3.815% APYMonthly compounding adds about 0.065 percentage points to the stated rate.
4.15% interest rate
4.230% APYOn $10,000 left for one year, that is about $423 before fees or taxes.
5.00% interest rate
5.116% APYOn $10,000 left for one year, that is about $512 before fees or taxes.
Decision guide
How to read the APY result
Annual percentage yield converts a stated rate and compounding schedule into one annualized comparison figure. Under Regulation DD, APY reflects the interest rate and compounding frequency over a 365-day period. The calculator is most useful when the nominal rate is known and stays constant for the modeled year.
5% nominal, compounded monthly
Enter 5 for the nominal annual rate and 12 compounds per year. The formula (1 + 0.05 / 12)^12 - 1 produces about 5.116% APY. Daily compounding produces a slightly higher result, but the difference is small compared with a fee, minimum-balance rule, introductory-rate expiration, or a lower underlying rate.
Before you decide
- Confirm whether the account advertises APY or a nominal rate.
- Use the institution's actual compounding schedule.
- Check balance tiers and rate-change conditions.
- Compare fees, withdrawal rules, and deposit insurance separately.
Method and limitations
This converter assumes the rate remains unchanged, interest stays in the account, and there are no deposits or withdrawals during the modeled year. Tiered, stepped, promotional, and term accounts can require institution-specific APY calculations. Use the bank's disclosure as the controlling figure for an actual product.