APY Calculator

Convert a nominal interest rate to Annual Percentage Yield (APY) for yearly, quarterly, monthly, or daily compounding. Free, instant, no signup.

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Formula: APY = (1 + r/n)^n − 1
  • r = nominal annual rate (decimal)
  • n = compounding periods per year

How to use the APY Calculator

  1. Enter your values. Fill in the fields with your numbers.
  2. Calculate. Press Calculate to run the apy calculator.
  3. Use the result. Copy the result or try a related tool next.

Why use our APY Calculator

Instant results. Enter your figures and the apy calculator returns an answer in seconds.
Free & private. Runs in your browser — no signup, and nothing is sent to a server.
Accurate. Uses standard formulas so you can rely on the numbers.

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About the APY Calculator

The APY Calculator turns a stated interest rate into the annual percentage yield you actually earn once compounding is included. Where a quoted rate (sometimes shown as APR on deposits) ignores how often interest is added back to your balance, APY captures the interest-on-interest effect over a full year. Enter the nominal rate and pick a compounding frequency, and the tool reports the true effective yearly return. It works for high-yield savings accounts, money market accounts, certificates of deposit, and any deposit product where the bank pays interest more than once a year.

Reach for this calculator whenever you are comparing two accounts whose headline numbers do not line up. A 5% rate compounded monthly is not the same as 5% compounded daily, and APY is the only figure that lets you compare them fairly. It is also useful for sanity-checking a bank's advertised APY against its stated rate, for estimating what your balance will earn before you open an account, and for understanding why an APY can be slightly higher than the rate printed in the headline. Savers shopping for the best return are looking for the highest APY, not the highest nominal rate.

The math follows the standard compound-interest identity: APY = (1 + r/n)^n - 1, where r is the nominal annual rate written as a decimal and n is the number of compounding periods per year (12 for monthly, 365 for daily, and so on). For example, a 5% rate compounded monthly gives (1 + 0.05/12)^12 - 1, or about 5.12%. The more frequently interest compounds, the larger the gap between the nominal rate and the APY, though the difference shrinks at high frequencies and approaches a ceiling as compounding nears continuous.

Every calculation runs entirely in your browser, so the rates and amounts you type are never sent to a server or stored. Results are mathematically exact for the formula above, but they are an estimate of real-world earnings: actual interest can differ if a bank changes its rate, applies tiered rates, credits interest on a schedule that differs from its compounding basis, or rounds at the penny. Under the Truth in Savings Act, banks must disclose both their APY and their compounding frequency, so use the figures from your account agreement for the most precise comparison.

Frequently asked questions

What is the difference between APY and interest rate?

The nominal interest rate is the base rate before compounding, while APY is the effective rate after compounding is applied. Because interest earns interest, the APY is always equal to or higher than the nominal rate, and the gap grows with more frequent compounding.

How is APY calculated?

APY uses the formula 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. A 5% rate compounded monthly works out to about 5.12% APY.

Is APY the same as APR?

No. APY measures interest you earn on a deposit and includes compounding, while APR measures the cost of borrowing and generally does not reflect compounding. For savings you want a high APY; for loans you want a low APR.

Does more frequent compounding always mean more money?

Yes, but with diminishing returns. Daily compounding earns slightly more than monthly at the same rate, but the difference is small and flattens out as compounding approaches continuous, so a higher nominal rate usually matters more than a more frequent compounding schedule.

Why is the bank's advertised APY higher than its stated rate?

Because APY bakes in the effect of compounding over a year. The stated rate is the base figure, and once interest is added back to your balance repeatedly throughout the year, the effective annual yield ends up higher.

From our blog

How to Count Cash Fast and Accurately with the Money Counter

By the Super Simple Digital Tools Team · Updated June 2026

Counting cash by hand is slow and surprisingly error-prone, especially once coins enter the mix. The reliable method professionals use is to separate the work into two stages: physically organize the money first, then let a calculator do the arithmetic. The Money Counter is built for that second stage. Once your cash is sorted into clean stacks by denomination, the tool turns a row of quantities into an exact total, removing the mental addition that causes most mistakes during a busy shift or a quick deposit.

Start by sorting. Make one pile for each denomination you have, so all the twenties are together, all the quarters are together, and so on. Counting within a single denomination is far easier than counting a jumbled handful, because every item in the pile is worth the same amount. For bills, fan them face-up in the same direction; for coins, group them in tens so a glance tells you the count. This preparation is what makes the final number trustworthy, since the calculator can only be as right as the quantities you give it.

Next, enter the quantities. Type the number of bills or coins for each denomination into its matching field and leave the rest at zero. The tool multiplies each quantity by its face value behind the scenes, then adds the products together for a single total. Because the values are fixed, there is nothing to round and nothing to estimate. If you are working in a currency other than US dollars, switch to that currency so the denomination list matches the notes and coins you are actually holding.

If you are balancing a register, the total is only half the job. Compare it against what you expected: take your opening float, add the cash you took in, and subtract any cash paid out, then check that against the counted figure. A difference means either a miscount or a transaction error. Many businesses tolerate a small variance of a dollar or two, but anything larger is worth recounting before you write it off, because a single misread stack of bills can throw the whole drawer off.

Finally, treat the count as repeatable rather than a one-off. The same routine works for a piggy bank, a tip jar, a fundraiser collection, or a coin sorting session with kids, and it scales from a few dollars to a full till. Recounting the highest-value stacks once more before you commit the number is a habit worth keeping, since errors on hundreds and twenties move the total the most. With sorting done well, the Money Counter gives you a precise figure every time.

  • Sort into one stack per denomination before entering anything; counting within a single value is far less error-prone than counting a mixed handful.
  • Group coins in tens (ten dimes, ten quarters) so you can verify each stack at a glance and reduce miscounts.
  • When balancing a drawer, compare the total to opening float plus cash in minus cash out, and recount before treating any gap as a real shortage.
  • Always recount the high-value stacks like fifties and hundreds twice, since a single error there shifts the total the most.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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