How APR is calculated
The Truth in Lending Act and its Regulation Z define two numbers behind every loan APR. The finance charge is the dollar cost of credit: interest plus the charges you pay as a condition of getting the loan, such as points, loan fees and premiums for insurance that protects the lender against default. The amount financed is, in short, the loan amount minus any prepaid finance charges you pay at closing.
The APR is the yearly rate at which the scheduled amortizing payments exactly repay the amount financed. Your payment is set by the note rate on the full loan amount, but the formula treats you as receiving less, so the APR comes out higher than the rate whenever there are upfront charges. Regulation Z requires the actuarial method or the United States Rule, and a disclosed APR counts as accurate if it is within 1/8 of a percentage point of the true figure, or 1/4 point for irregular loans with uneven payments or advances.
On a Mortgage, the Loan Estimate shows the interest rate on page 1 and the APR on page 3, under Comparisons. If the APR on the Closing Disclosure becomes inaccurate before closing, the lender must give you corrected disclosures at least three business days before you can close.
What a mortgage APR includes and leaves out
The table below sorts common closing costs using Regulation Z’s definitions. A charge that is a condition of the credit goes into the APR unless the rule specifically excludes it. Certain real-estate charges that a cash buyer might pay too, such as title work and an appraisal, stay out when they are bona fide and reasonable in amount. Property taxes stay out because a cash buyer pays them too, and homeowners insurance usually does, as long as you may choose the insurer.
That is why two loans with the same rate can show different APRs: one lender charges a 1% origination fee or sells you discount points, and the other doesn’t. One discount point costs 1% of the loan amount and buys a lower rate. It is also why APR is an incomplete measure of cost. Excluded items such as title insurance can still add thousands of dollars, and the APR says nothing about the cash you need at closing, your escrow payment or whether the loan carries a prepayment penalty. Read the Loan Estimate’s closing-cost pages alongside it.
APR vs. interest rate, APY and your real cost
The interest rate sets your payment. The APR folds in upfront finance charges to show the yearly cost of the credit. For savings, the matching measure is the annual percentage yield (APY), which includes compounding. A loan APR doesn’t: like any nominal interest rate, it is the periodic rate times the number of periods, so a card charging 2% a month has a 24% APR but costs about 26.8% a year if the interest is left unpaid.
The biggest limit is time. A mortgage APR assumes you keep the loan for its full term, which spreads upfront points over 30 years. Many loans end sooner through a sale or Refinancing, and the shorter a loan lasts, the more its upfront charges cost per year, as the example below shows. For an adjustable-rate mortgage, the CFPB cautions that the APR may not reflect the maximum rate the loan can reach, so compare the rate caps too.
- Compare APR with APR and rate with rate; mixing one lender’s rate with another’s APR misleads.
- Check what happens when a 0% introductory APR ends or a variable rate resets.
How credit card APRs work
On a credit card, the APR is the periodic rate multiplied by the number of periods in a year: a 1.5% monthly rate is an 18% APR. The CFPB notes that on most cards you can avoid interest on purchases entirely by paying the full balance by the due date. Cards often carry separate APRs for purchases, balance transfers and cash advances, and a variable APR moves with a published index, such as the prime rate, that the issuer doesn’t control.
Card rates are high. The Federal Reserve’s G.19 release of September 8, 2026 put the average APR across all credit card accounts at commercial banks at 20.94% in the second quarter of 2026, and 22.15% on accounts that were actually charged interest. That is why card balances usually sit at the top of a debt avalanche payoff plan.
Regulation Z, which carries out the Credit CARD Act of 2009, limits when an issuer can raise your card’s APR:
- An introductory or other temporary rate must last at least six months, and the rate that follows must be disclosed in advance.
- An issuer generally can’t raise the rate on a new account during its first year, apart from a variable-rate index change, a promotion ending or serious delinquency.
- Most rate increases need written notice at least 45 days ahead and can’t apply to balances run up before the notice.
- A higher rate on existing balances is allowed once a minimum payment is more than 60 days late, and it must come back down after six consecutive on-time payments.
Illustrative numbers
Two $400,000, 30-year offers: lower APR vs. lower cost
- Amount financed
- The loan amount minus prepaid finance charges such as points and origination fees
- payment
- The scheduled monthly payment, set by the note rate on the full loan
- t
- The number of each payment, from 1 to n
- n
- The total number of monthly payments
- APR
- The annual rate the lender solves for, stated as a nominal yearly rate
There is no closed-form answer; lenders solve for the APR by iteration, as a spreadsheet RATE function does.
Loan A: 6.95%, no points, $3,000 in lender feesPayment $2,647.79; APR 7.025%
Loan B: 6.75%, 1 point ($4,000) plus $3,000 in lender feesPayment $2,594.39; APR 6.923%
Monthly payment saved with Loan B$53.40
Interest plus fees if the loan ends after 3 yearsA: $85,109; B: $86,698
Interest plus fees if the loan ends after 10 yearsA: $263,580; B: $259,531
Loan B shows the lower APR because the formula spreads its extra $4,000 of points across all 360 payments. If the loan ends within about five years, through a sale or a refinance, Loan A costs less in interest and fees; keep it longer and Loan B pulls ahead, by about $4,000 after 10 years.
At a glance
How common mortgage costs are treated in the APR under Regulation Z
| Cost | In the APR? | Why |
|---|---|---|
| Interest at the note rate | Yes | The core finance charge |
| Discount points and origination fees | Yes | Points and loan fees are finance charges |
| Mortgage broker fees | Yes | Included by a specific rule for broker fees |
| Mortgage insurance premiums | Yes | Insurance protecting the lender against default |
| Title search and title insurance | No | Excluded real-estate fee if bona fide and reasonable |
| Appraisal and inspection fees | No | Excluded real-estate fee if bona fide and reasonable |
| Credit report, notary and document preparation | No | Excluded real-estate fees if bona fide and reasonable |
| Property taxes paid through escrow | No | A cost a cash buyer pays too |
| Homeowners insurance | Usually no | Excluded when you may choose the insurer and the premium is disclosed |
| Application fee charged to every applicant | No | Excluded when all applicants pay it, approved or not |
Put it in your plan
APR in MoneyWhatIf
MoneyWhatIf takes a standalone debt’s balance, annual interest rate and either a remaining term or a monthly payment, then works out interest and principal month by month from that rate. Enter the rate that sets the payment, not the APR: upfront costs are entered as cash instead, and a future home purchase takes closing costs alongside the down payment, so folding them into the rate would count them twice. Debt entries don’t add lender fees or promotional-rate schedules, so for a card with an introductory rate, enter the rate you expect to pay over the years being modeled.
Common questions
APR FAQs
Why is my APR higher than my interest rate?
Because the APR adds the finance charges you pay to get the loan, such as points, origination and broker fees and mortgage insurance, to the interest. The payment is computed on the full loan at the note rate, but Regulation Z treats you as receiving the loan minus those charges, which raises the effective yearly rate. A loan with no such charges has an APR equal to its rate.
Is a lower APR always the better loan?
Not always. APR assumes you keep the loan for its whole term, which favors paying points up front to buy a lower rate. If you are likely to move or refinance within a few years, an offer with fewer upfront costs and a slightly higher APR can cost less. Compare the closing costs on each Loan Estimate, then add up interest plus fees over the number of years you actually expect to keep the loan.
How is credit card interest calculated?
If your card uses a daily periodic rate, that rate is the APR ÷ 365. The issuer applies it to your balance each day of the billing cycle and adds up the charges. At 22.15%, the average on accounts charged interest in the second quarter of 2026, carrying $2,000 through a 30-day cycle costs about $36. Paying the full statement balance by the due date usually avoids interest on purchases; a balance you carry keeps accruing it, and unpaid interest added to the balance compounds.
Does a credit card’s APR include its fees?
No. For a credit card, Regulation Z computes the APR by multiplying the periodic rate by the number of periods in a year, so it reflects interest alone. Annual fees, balance-transfer and cash-advance fees and late fees are disclosed separately in the card’s rate and fee table. That is the opposite of a mortgage APR, which folds points and other finance charges into the rate, so compare cards on both the APRs you will actually pay and their fees.
What is a good credit card APR?
There is no official benchmark, but Federal Reserve data give context: the average APR across all bank credit card accounts was 20.94% in the second quarter of 2026. The rate you are offered depends largely on your credit score and the type of card. If you pay the full balance every month, the APR rarely matters; if you carry a balance, it is often the most expensive debt you have.