APR to APY Converter

Comparing a loan's Annual Percentage Rate to a savings account's Annual Percentage Yield only makes sense once you convert one into the other — that's exactly what this APR APY Converter does, turning a stated rate into its compounded equivalent in either direction. Enter a number above and it instantly shows what you'd actually earn or pay once compounding is factored in. Whether you're sizing up a credit card offer or comparing deposit options, the sections below walk through the math so the figure on screen actually makes sense.

How This APR APY Converter Works

Enter a rate and choose how often interest compounds — daily, monthly, quarterly, or yearly — and the calculator returns the annual percentage yield you'd actually receive over a full year. Switch modes and it works in reverse: type in an APY and the tool solves back to the rate a lender must be quoting. Used as an apr to apy calculator or, in reverse, an apy to apr calculator, both directions rely on the same handful of variables: the rate itself, how many times a year it compounds, and time.

What You Enter and What You Get Back

You don't need to know which formula applies before you start — tell the calculator what you have and it picks the right direction automatically.

• Rate type — whether the figure you're starting with is a nominal APR or an already-compounded APY.
• Compounding frequency — daily, weekly, monthly, quarterly, twice a year, or continuous.
• Starting figure (optional) — a balance lets you see the dollar amount of interest earned or owed, not just the percentage.

What Is Annual Percentage Yield (APY)?

Annual percentage yield is the annual rate of return once compound interest is factored in. Where APR only accounts for simple interest, APY captures the fact that interest earned in one compounding period starts earning interest itself in the next — which is why banks tend to advertise APY on deposit products, since it makes the effective yield look higher than the underlying figure alone.

Compound Interest Is What Separates APY From APR

The more frequently a balance compounds, the further its APY drifts above the underlying APR. A 6% rate compounded once a year stays at 6% APY, but the same rate compounded daily pushes past 6.18% — the extra return comes entirely from interest being credited, and then earning interest, more often during the year.

Compounding Frequency Changes the Result

The same nominal annual rate produces a different APY depending entirely on compounding frequency. Weekly compounding, monthly compounding, and daily compounding all push a stated rate progressively closer to its mathematical ceiling. The table below shows a 6% APR converted to APY across the schedules you'll actually encounter on real accounts.

Continuous Compounding Explained

Continuous compounding is the mathematical limit of how often a figure can compound — interest is calculated and added at every instant rather than at fixed intervals. It relies on Euler's number (e ≈ 2.71828) instead of a discrete count of periods:

$$APY = e^{r} - 1$$

No real account actually compounds continuously, but the concept shows up in options pricing (the Black-Scholes model leans on it heavily) and in theoretical finance, where it simplifies combining rates from different sources. Some sites label this same math an EAR calculator, since EAR and APY describe the same effective number once compounding is included.

Where You'll Use an Interest Rate Converter

An interest rate converter like this one is useful anywhere a bank, lender, or financial institution quotes a figure, because the number on the page is rarely the number you'll actually experience.

Savings Accounts and CDs

• Comparing high-yield savings options by their effective return rather than the headline number.
• Estimating how much a certificate of deposit will actually pay before you lock in a term.
• Checking whether a money market account's compounding schedule meaningfully changes what you'll actually earn.

Credit Cards and Mortgages

• Understanding how daily compounding on a revolving balance can make the real cost of a purchase higher than the printed APR suggests.
• Translating a home loan's APR into an effective annual rate calculator result for a clearer side-by-side comparison of offers.
• Checking a personal loan's true annual cost once financing fees and prepaid fees are folded into the total.

This kind of conversion is a genuinely practical piece of personal finance and banking know-how — the same handful of formulas apply whether you're evaluating a credit union CD or a national lender's home loan.

Common Mistakes When Comparing APR and APY

Most APR-versus-APY confusion comes down to comparing numbers that aren't actually on the same basis.

• Comparing a loan's APR directly to a deposit's APY instead of converting both to the same type first.
• Ignoring fees, minimum-balance requirements, or promotional terms that an advertised yield doesn't disclose up front.
• Assuming every account or loan compounds on the same schedule — daily, monthly, and quarterly compounding on an identical rate produce different real-world results.

Mixing a Nominal Rate With an Effective Rate

The most frequent error is treating a stated figure and a compounded figure as interchangeable. A 12% nominal rate and a 12% effective rate are not the same investment — one already includes the effect of compounding, the other doesn't — and mixing them up when comparing a loan to a deposit can lead to a materially wrong conclusion about which option is actually better.

Whatever pair of numbers you're starting from, running them through this converter first is the simplest way to make sure you're comparing loans, deposits, and investment products on genuinely equal footing.