APR vs. APY: What’s the Difference and Why It Matters

One Letter Apart, Opposite Sides of Your Wallet

APR and APY look almost the same. They are one letter apart. But they sit on opposite sides of your money. APR (annual percentage rate) is what you pay to borrow. APY (annual percentage yield) is what you earn to save. Mix them up and you can misjudge a loan or a savings account by real dollars.[1, 15]

Here is the tilt you should notice: lenders advertise APR, the number that looks smaller. Banks advertise APY, the number that looks bigger. Neither side is lying. U.S. law tells each of them which number to show, precisely so you can compare offers fairly — within the same category.[15, 19]

This guide breaks down the exact difference, the compounding math that separates the two, and the traps that cost people money. You will also learn how to convert one into the other yourself. Start by seeing what compounding — the engine behind APY — can do to money over time.[22]

The Difference in One Sentence

Here is the whole idea in one line: APR ignores compounding within the year; APY includes it. An APR is a simple yearly rate. It does not show what happens when interest starts earning interest. An APY does. It bakes the compounding right into the number.[15, 6]

A quick way to hold it in your head: APR is a cost, APY is a yield. With a cost, lower is better — you want to pay less to borrow. With a yield, higher is better — you want to earn more when you save. For the same nominal rate, APY is always equal to or higher than APR, because compounding only ever adds.

The federal banking regulator OCC keeps clean plain-English definitions of both. It calls APR “the cost of credit on a yearly basis, expressed as a percentage,” and APY “a percentage rate reflecting the total amount of interest paid on a deposit account based on the interest rate and the frequency of compounding.” Same idea, two sides.[15]

What APR Really Means (and Where It Comes From)

APR is not a marketing term. It is a legal one. It comes from the Truth in Lending Act, a 1968 law whose whole purpose is “to assure a meaningful disclosure of credit terms so that the consumer will be able to compare” offers. The rules that make it work live in Regulation Z.[19, 8]

Regulation Z defines the APR as “a measure of the cost of credit, expressed as a yearly rate.” The law is strict about it: for most closed-end loans, the disclosed APR must be accurate to within one-eighth of one percentage point. And how it is calculated is set by statute — 15 U.S. Code § 1606 — so a lender cannot invent its own math.[9, 20]

One more thing that surprises people: on many loans, the APR is broader than the interest rate. It folds in certain fees you pay to get the loan — like points and some closing costs. That is why a mortgage APR is usually a little higher than the note rate. We come back to this in the loans section below.[3]

What APY Really Means (and Where It Comes From)

APY has its own law: the Truth in Savings Act. Its goal is the mirror image of the lending law — to let “consumers make a meaningful comparison between the competing claims of depository institutions.” Banks follow Regulation DD; credit unions follow the NCUA’s Part 707.[21, 6, 13]

Regulation DD defines the APY as “a percentage rate reflecting the total amount of interest paid on an account, based on the interest rate and the frequency of compounding for a 365-day period.” The same rule draws the line clearly: the plain “interest rate” is “the annual rate of interest … which does not reflect compounding.” That single sentence is the whole APR-vs-APY story in miniature.[6]

Because APY includes compounding, it is “the primary uniform measurement for consumer comparison shopping” across banks, thrifts, and credit unions, as the NCUA puts it. The exact formula is fixed in Appendix A of Regulation DD, so a 4.00% APY at one bank means the same thing as a 4.00% APY at another. That is the point.[14, 7]

The Math That Turns One Into the Other

Compounding is simple to picture. When your interest earns interest, the total grows a little faster than a flat rate suggests. The more often it compounds — yearly, monthly, daily — the bigger the gap between the plain rate (APR-style) and the real yearly result (APY).[22]

Here is the one formula worth knowing. If r is the nominal annual rate and n is how many times a year it compounds, then APY = (1 + r/n)ⁿ − 1. Take a 12% nominal rate compounded monthly. That is 1% a month. Over 12 months the APY is (1.01)¹² − 1 = 12.68%. Same starting rate, higher real number — that is compounding at work.

This cuts both ways. On savings, compounding works for you, and the APY shows the reward. On a debt, the very same compounding works against you — which is exactly why a credit card that quotes an APR can cost you a touch more than that number suggests. That is the next section.

Why Lenders Show APR and Savers Get APY

It is not random which number shows up where. On the borrowing side, the law requires APR. On the saving side, the law requires APY. Each rule exists so you can compare like with like: one loan’s APR against another loan’s APR, one account’s APY against another account’s APY.[19, 21]

The FTC says it plainly for shoppers: knowing the APR “makes it easier to compare ‘apples to apples’ when you’re choosing” a loan, because “the APR … is the total cost you pay for credit, as a yearly rate.” The FTC even notes that “under federal law if the interest rate is in the ad, the APR also should be there.”[17]

So the takeaway is not “APR bad, APY good.” It is: use the number the law made for that job. Just never carry an APR across the fence to compare it head-on with an APY. They are measured differently. Next, see the one place where an APR quietly costs a bit more than it looks — the credit card.

Credit Cards: Where APR Hides Daily Compounding

A card shows you a purchase APR — say 21%. But most cards do not charge that once a year. They charge it every day. The CFPB explains that “the daily periodic interest rate generally can be calculated by dividing the annual percentage rate, or APR, by either 360 or 365,” and then interest “is compounding on a daily basis.”[2, 1]

Daily compounding means the true yearly cost of carrying a balance is a hair higher than the stated APR — the APR’s own APY, if you like. It also means one card is rarely just one APR. There is usually a separate purchase APR, balance-transfer APR, cash-advance APR, and a penalty APR if you fall behind. Many are “variable,” tied to the bank prime rate.[11]

These are not small rates today. As of the Federal Reserve’s most recent G.19 data (fourth quarter 2025), the average APR was 21.00% across all card accounts and 21.52% on accounts actually charged interest. For a deeper look at how card interest and minimum payments interact, see our guide to credit card interest and minimum payments.[10]

Loans: Why APR Is Your Best Comparison Number

On a closed-end loan — a mortgage, a car loan, a personal loan — the APR is designed to be your single best comparison number. That is because it can fold in fees, not just the interest rate. The CFPB puts it cleanly: “The APR reflects the interest rate, any points, mortgage broker fees, and other charges that you pay to get the loan.” The plain interest rate “does not reflect fees or any other charges.”[3]

This is why a mortgage APR usually sits a bit above the note rate. If you pay discount points to buy down your rate, those upfront costs show up in the APR. The FTC’s advice for shoppers is blunt: “don’t focus only on the monthly payment” — the total depends on the price, the APR, and the length of the loan.[4, 18]

One caveat: the disclosed APR assumes you keep the loan to the end. If you sell the house or refinance early, a loan with heavy upfront points can end up costing more per year than its APR suggested, because you spread those fees over fewer years. For a fee-heavy comparison across products, our guide to personal loans walks through the trade-offs.[17]

Savings, CDs, and Money Markets: APY Is Your Yield

On the saving side, APY is the number to trust. Because it already includes compounding, a 4.50% APY savings account and a 4.50% APY certificate of deposit (CD) are earning you the same yearly rate, even if one compounds daily and the other monthly. That is the whole convenience of APY: it does the compounding math for you.[16, 6]

But the number you are quoted matters enormously. As of the FDIC’s National Rates (June 15, 2026), the national average savings APY was just 0.38%. Meanwhile, competitive high-yield accounts commonly pay many times that. Same three letters, wildly different reward — which is why you always read the actual APY, not “interest rate,” and not the average.[12]

A few things can shrink a shiny APY: an intro or promo rate that drops later, a tiered rate that only applies above a high balance, or a minimum balance you must keep to earn it. Read those conditions before you move money. For how to stack accounts and ladder CDs, see our guide to high-yield savings and CD laddering.[13]

APR vs. APY in Real Numbers

Start with the same nominal rate, 5%, and watch it split. As a loan APR, it is simply 5.00%. As a savings rate compounded daily, the APY is about 5.13%. Same headline number, two different results — one is a cost that ignores compounding, the other a yield that counts it.

Now the mistake to avoid: comparing a 6.99% APR car loan against a 4.50% APY savings account and concluding “borrowing costs more than saving earns.” They are on opposite sides of the fence. One is what you pay a lender; the other is what a bank pays you. The gap between them is not a single “spread” you can act on — they are two different measurements.[18]

The most jarring example is the payday loan. The CFPB notes that “a typical two-week payday loan with a $15 per $100 fee equates to an annual percentage rate (APR) of almost 400 percent.” Run the math yourself — $15 on $100 over 14 days, annualized — and you land near 391%. A small-looking fee becomes a giant APR once you express it as a yearly rate.[5]

How to Convert APR to APY (and Back)

To go from a nominal APR to an APY, use the compounding formula again: APY = (1 + APR/n)ⁿ − 1, where n is the number of compounding periods per year. A 6% APR compounded monthly becomes (1 + 0.06/12)¹² − 1 = about 6.17% APY. Compounded daily, it is closer to 6.18%. More frequent compounding, slightly higher APY.[7]

To go the other way — from an APY back to a nominal rate — the formula flips: nominal rate = n × [(1 + APY)^1/n − 1]. You rarely need this by hand. The point of both formulas is simply to see that APR and APY are two views of the same underlying rate, split apart by how often interest compounds.

If you would rather skip the exponents, let a calculator do it. Plug your rate and a compounding frequency into a compound-interest tool and watch the yearly result appear — that result is the APY. It is the fastest way to feel how a stated rate turns into real money over time.[22]

Common APR and APY Mistakes

Mistake one: comparing an APR to an APY head-on. As we have seen, they are measured on opposite sides. Mistake two: assuming an APR includes compounding. The stated APR is a simple rate; the daily compounding on a card means your real cost is a bit higher. Mistake three: ignoring the fees folded into a mortgage APR, then being surprised it sits above the interest rate.[3, 2]

Mistake four is the expensive one: treating “0% APR” as free. Sometimes it truly is a great deal. But watch for two catches. On store-card “deferred interest” offers, if you do not clear the full balance in time, interest can be charged back to day one. And a 0% car deal may require giving up a cash rebate — so compare the total cost of each path, not just the rate.[18]

The 10-Second Cheat Sheet

When you see APR: it is a cost. Lower is better. It may include fees. It ignores compounding within the year. It shows up on credit cards, mortgages, car loans, and personal loans.[15]

When you see APY: it is a yield. Higher is better. It already includes compounding. It shows up on savings accounts, CDs, and money market accounts. And the golden rule: only compare APR to APR, and APY to APY — never across the fence.

One last habit worth building: whenever a rate is in front of you, ask “is this a cost or a yield, and does it include compounding?” That single question keeps APR and APY straight for life. If you are shopping for a card, our guide on how to choose a credit card puts the APR in context.

Frequently Asked Questions