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APR and APY describe different things in the US borrowing and bank-deposit contexts covered here. A loan’s annual percentage rate, or APR, measures its yearly cost of credit and can reflect applicable fees as well as interest. A deposit’s annual percentage yield, or APY, expresses interest over a year with compounding taken into account. The larger percentage is not automatically the better deal: first identify the product and what the figure measures.
There is also an important third number: the interest rate. A nominal annual interest rate of 5%, compounded monthly under the simplified assumptions below, produces an effective annual yield of about 5.11619%. That calculation starts from an interest rate, not from a loan APR.
What APR and APY tell you
This guide uses US closed-end consumer lending and consumer bank-deposit disclosures under Regulation DD. Closed-end loans have an agreed repayment arrangement, unlike revolving credit. Credit-card calculations, other jurisdictions and investment-product labels need their own rules.
| Figure and context | What it describes | What to check alongside it |
|---|---|---|
| Loan interest rate | The rate used to charge interest on the borrowing | Fees, the balance used and the repayment schedule |
| Closed-end loan APR | Yearly cost of credit under the applicable calculation rules | Included finance charges, amount financed and payment timing |
| Deposit interest rate | The annual interest rate before reflecting compounding | Compounding frequency and the balance or rate tier that applies |
| Deposit APY | Interest expressed as an annual yield, reflecting compounding under the disclosure assumptions | Whether the rate can change, account conditions and charges |
For deposits covered by Regulation DD’s definitions, interest rate and APY are distinct: the interest-rate definition does not reflect compounding, while APY does. That distinction should not be turned into a claim that every loan quoting an APR uses simple interest.
Why a loan’s APR can differ from its interest rate
The CFPB’s loan explanation distinguishes the interest rate from APR, which also reflects additional lending charges such as an applicable origination charge. Its worked context is auto lending. Comparing one offer’s APR with another offer’s interest rate mixes two different measures.
For closed-end credit, Regulation Z § 1026.22 relates the amounts and timing of value received to the amounts and timing of repayments. APR is therefore not simply a fee percentage added to an interest-rate percentage. The loan’s cash flows and applicable calculation method matter.
Nor does APR mean that every possible cost is included. Regulation Z’s finance-charge rules include charges that qualify and contain exclusions. Read the actual disclosures and charges rather than assuming a single percentage captures every expense.
A useful comparison keeps the loan amount, term and repayment structure in view as well as the APR. This article does not calculate a loan’s APR or use a deposit-growth formula to reconstruct one.
How a 5% interest rate becomes about 5.11619%
Take an invented deposit-style calculation with these assumptions:
- The starting balance is 1,000 currency units, abbreviated CU.
- The nominal annual interest rate is fixed at 5% for one full year.
- Interest is added at the end of each of 12 monthly periods, using a periodic rate of 0.05 ÷ 12.
- All interest stays in the balance and earns interest in later periods.
- There are no further deposits, withdrawals, fees or taxes. Calculations retain unrounded values until display.
The monthly rate is 0.05 ÷ 12, or approximately 0.4166667%. The balance is multiplied by the same factor, 1 + 0.05/12, twelve times:
Effective annual yield = [(1 + 0.05/12)¹² − 1] × 100 ≈ 5.11619%.
The end balance is 1,000 × (1 + 0.05/12)¹² ≈ 1,051.1619 CU. Interest for the year is about 51.1619 CU. The extra interest beyond 50 CU comes from leaving earlier interest in the balance to earn interest too.
| Point in the example | Balance calculation | Balance, rounded to four decimals (CU) |
|---|---|---|
| Start | 1,000 | 1,000.0000 |
| After month 1 | 1,000 × (1 + 0.05/12) | 1,004.1667 |
| After month 6 | 1,000 × (1 + 0.05/12)⁶ | 1,025.2619 |
| After month 12 | 1,000 × (1 + 0.05/12)¹² | 1,051.1619 |
The input here is a nominal annual interest rate. Substituting a quoted loan APR into this equation would not establish a deposit APY or the loan’s actual cost: fees and repayment cash flows cannot be discarded that way.
This is a teaching calculation, not a bank offer or a complete regulatory APY calculator. Regulation DD’s Appendix A supplies the disclosure rules, including the term and day-count treatment and special cases. Its general assumptions keep principal and interest on deposit without other transactions, subject to exceptions such as required interest withdrawals.
Why an advertised APY can differ from your outcome
A variable-rate account’s quotation is not a promise to keep today’s interest rate for a year. For an account without an introductory premium or discount, Appendix A’s disclosure calculation assumes the initial interest rate remains unchanged. The actual rate may change. Introductory and stepped rates have additional calculation rules.
Balance tiers matter too. The quoted yield may depend on the balance level and whether the stated rate applies to the whole balance or only part of it. Check the rate tier and account conditions before applying an advertised percentage to an amount of money.
APY is an interest measure, not your complete financial outcome. Account charges and taxes need separate treatment; neither is deducted in our example. It also does not measure inflation-adjusted purchasing power. The nominal-versus-real-return guide explains that separate adjustment.
An investment or crypto service using the letters APR or APY still needs its own explanation of the calculation, asset, risks and withdrawal terms. The label alone does not establish that the product is a bank deposit or that its projected yield will be realized.
Compare figures that answer the same question
For borrowing, compare APR with APR for comparable loans, then read the amount financed, payment schedule and charges. An interest rate alone does not answer the same cost question.
For covered bank deposits, compare APY with APY, then check rate variability, compounding assumptions, balance conditions and charges. Do not compound an APY again as if it were a nominal annual interest rate.
For an investment’s historical performance, first identify the holding period and included cash flows. That is the separate task covered by annualized versus total return; it does not turn a past result into a quoted deposit yield.
Questions about APR and APY
Can I convert a loan APR directly into APY?
Not as a general rule. The simple compounding equation above needs a nominal annual interest rate and an explicit compounding schedule. A regulated loan APR can reflect finance charges and repayment timing. Calling its result APY would not preserve that loan information.
Is APY always higher than the interest rate?
Not always. In the fixed, positive-rate example with monthly compounding, the effective yield exceeds the nominal annual interest rate. With the same setup but compounding only once at year-end, both would be 5%. Real deposit disclosures can also involve special rules, so read the account terms.
Is the term APR used only for loans?
No. Regulation DD permits a covered deposit’s interest rate to be described as an annual percentage rate as well as an interest rate. In that deposit definition, it does not reflect compounding. Identify the product and definition instead of assuming the letters always mean the same calculation.
Does a quoted APY guarantee what I will have next year?
No. The calculation has assumptions about the rate, term and money remaining in the account. Rate changes, transactions, account conditions and charges can change the result. An advertised annual yield is not a guarantee of your personal after-tax outcome.
Does a loan APR tell me the total amount I will repay?
It is a rate, not a dollar total. The amount borrowed, financing charges and payment schedule are needed to understand the total payments. Do not multiply an APR by an arbitrary balance and time span and treat that as a complete loan repayment calculation.
Sources
- CFPB: What is the difference between a loan interest rate and the APR? — consumer explanation in an auto-loan context; page marked last reviewed 28 August 2026.
- Regulation Z § 1026.4: Finance charge — finance-charge definition and exclusions.
- Regulation Z § 1026.22: Determination of annual percentage rate — closed-end APR and payment-timing context.
- Regulation DD § 1030.2: Definitions — covered deposit accounts, interest rate, APY and variable-rate definitions.
- Regulation DD Appendix A: Annual percentage yield calculation — disclosure assumptions, variable rates and balance tiers.
Source texts checked on 20 October 2026. The 5% rate and 1,000-CU balance are invented teaching inputs, not current product rates.
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Sources and scope
Published by HypaForecast. This educational comparison of US rate disclosures is not a product offer or recommendation.
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