APY Calculator
By Talcart · Last updated July 10, 2026
APY (Annual Percentage Yield) Guide
Understanding APY
Basic Formula
- APY = (1 + r/n)^n - 1
- Where: r = Nominal rate, n = Number of compounding periods per year
- Example: 6% nominal rate compounded monthly: (1 + 0.06/12)^12 - 1 = 6.17% APY
Compounding Frequencies
- Daily: 365 times per year
- Weekly: 52 times per year
- Monthly: 12 times per year
- Quarterly: 4 times per year
- Semi-annually: 2 times per year
- Annually: Once per year
APY Calculator
This APY calculator converts a nominal (stated) interest rate into the annual percentage yield you actually earn once compounding is included: a 5% rate compounded monthly is really 5.116% APY, and compounded daily it is 5.127%. Because banks quote rates in different ways, APY is the only number that lets you compare savings accounts, CDs, and money-market funds on equal footing.
Key facts
- A 5% nominal rate equals 5.000% APY with annual compounding, 5.116% with monthly, and 5.127% with daily -- the continuous-compounding ceiling is 5.1271%.
- A 6% nominal rate compounded monthly works out to 6.17% APY, so a $10,000 balance earns $616.78 in a year, not $600.
- APY = (1 + r/n)^n - 1 is never smaller than the nominal rate r; the two are equal only when interest compounds exactly once per year.
What is the APY Calculator?
Annual percentage yield (APY) is the effective annual rate of return on a deposit, reflecting both the nominal interest rate and how often interest compounds within the year. Unlike APR, which states simple annualized interest, APY captures the interest-on-interest effect, so APY is always greater than or equal to the nominal rate whenever compounding occurs more than once a year. In the United States, the Truth in Savings Act requires banks to disclose APY on deposit products precisely so consumers can compare offers directly.
How does the APY Calculator work?
The calculator applies APY = (1 + r/n)^n - 1, where r is the nominal annual rate as a decimal and n is the number of compounding periods per year. It divides the rate across n periods, compounds it n times, and reports the effective annual growth. As n increases the result rises toward a hard ceiling of e^r - 1 (continuous compounding): at 5% nominal, annual compounding yields exactly 5%, monthly yields 5.116%, daily yields 5.1267%, and the continuous limit is 5.1271% -- gains shrink rapidly beyond monthly.
What is the APY Calculator formula?
- r – nominal annual rate (decimal)
- n – compounding periods per year
Nominal Rate vs APY by Compounding Frequency
| Nominal Rate | APY (Monthly Compounding) | APY (Daily Compounding) |
|---|---|---|
| 1% | 1.005% | 1.005% |
| 2% | 2.018% | 2.020% |
| 3% | 3.042% | 3.045% |
| 4% | 4.074% | 4.081% |
| 5% | 5.116% | 5.127% |
| 6% | 6.168% | 6.183% |
| 8% | 8.300% | 8.328% |
| 10% | 10.471% | 10.516% |
How do you use the APY Calculator?
- Enter the nominal annual rate.
- Pick the compounding frequency.
- Read the effective APY and total return on a chosen balance.
Worked example
| Scenario | 6% nominal compounded monthly |
| Calculation | (1 + 0.06/12)^12 − 1 = 0.0617 |
| Result | APY ≈ 6.17%. |
Common use cases
Tips & best practices
Always compare APY (not APR) when shopping savings products.
Frequently asked questions
APR is the simple annualized rate that ignores intra-year compounding, while APY includes compounding and shows what you effectively earn. A 6% APR compounded monthly equals a 6.17% APY. The gap widens with higher rates and more frequent compounding. Banks typically advertise APY on savings products (it looks larger) and APR on loans (it looks smaller), so always match like with like.
Very little beyond monthly compounding. A 5% nominal rate produces 5.000% APY compounded annually, 5.0625% semiannually, 5.0945% quarterly, 5.116% monthly, and 5.1267% daily; the theoretical maximum with continuous compounding is 5.1271%. The entire jump from daily to continuous is less than half a basis point, so frequency matters far less than the headline rate itself.
Exactly $450, because APY already bakes in compounding: multiply the balance by the APY to get one year of interest. That is the convenience of the measure -- no further adjustment for frequency is needed. Over multiple years the balance itself compounds, so $10,000 at 4.5% APY becomes $10,450 after year one and $10,920.25 after year two.
For pure yield, yes -- APY exists precisely to make accounts directly comparable regardless of compounding schedule. But check the fine print: minimum balances, promotional periods after which the rate drops, monthly fees that offset interest, and withdrawal limits can all reduce your real return. A 5.00% APY account with a $10 monthly fee nets less than a 4.75% no-fee account on balances under about $50,000.
No. With annual compounding APY equals the nominal rate exactly, and with any more frequent compounding APY exceeds it. If a quoted "yield" is below the stated rate, fees or a different measurement basis are involved rather than pure interest math. The formula (1 + r/n)^n - 1 is mathematically greater than or equal to r for all n of at least 1.
Not directly -- APY describes deposit products with a fixed, guaranteed rate, such as savings accounts and CDs. Stocks and funds have variable returns, so their compound performance is expressed as CAGR (compound annual growth rate) instead, which is measured after the fact rather than promised in advance. The two are mathematically similar: both express effective annual compound growth.