APR Calculator

About APR Calculator

What Is APR and Why Does It Matter?

The nominal interest rate only tells you part of the story. APR (Annual Percentage Rate) rolls all borrowing costs into a single rate, making it possible to compare loans fairly. Under the Truth in Lending Act (TILA) in the US and the Consumer Credit Act in the UK, lenders are required to disclose the APR.

Example: Two mortgage offers for $300,000 over 30 years:

	Loan A	Loan B
Interest rate	6.25%	6.50%
Origination fee	$6,000 (2%)	$0
Other fees	$3,000	$1,500
Total fees	$9,000	$1,500
Monthly payment	$1,847	$1,896
APR	6.52%	6.54%

Loan A has a lower interest rate but higher fees. Once fees are included, the APRs are nearly identical. Loan B might actually be better if you plan to refinance or sell within a few years, because the lower upfront cost matters more over short periods.

How Is APR Calculated?

APR is the interest rate that would produce the same monthly payment if all fees were added to the loan balance. The formula is iterative (solved with Newton's method), but the concept is simple:

Effective Loan Amount = Principal + All Fees

APR = rate where payment on Effective Loan Amount equals actual payment on original Principal

Worked example: $200,000 loan at 6% for 30 years with $4,000 in fees:

• Monthly payment (on $200,000 at 6%): $1,199.10
• Effective loan amount: $204,000
• APR is the rate where $204,000 produces a $1,199.10 payment over 360 months: 6.18%
• The 0.18% APR increase reflects the $4,000 in fees spread over 30 years

What Fees Are Included in APR?

Included in APR	Not Included in APR
Origination/underwriting fees	Home inspection
Discount points	Title search fees
Mortgage broker fees	Title insurance (in most cases)
Closing costs charged by lender	Recording fees
PMI (private mortgage insurance)	Appraisal (varies by lender)
Prepaid interest	Attorney fees

The line between included and excluded fees varies by lender and regulation. When comparing APRs from different lenders, ask which fees are factored in. Some lenders exclude optional fees to make their APR look lower.

APR vs APY: Two Different Measures

These terms sound similar but measure different things:

	APR	APY (or EAR)
Stands for	Annual Percentage Rate	Annual Percentage Yield
Includes compounding?	No	Yes
Used for	Loans (what you pay)	Savings (what you earn)
Example at 6% monthly compound	6.00%	6.17%
Regulation	TILA (Truth in Lending)	TISA (Truth in Savings)

For loans, APR is the standard disclosure. For savings accounts and CDs, look at APY. A savings account advertising 5% APR compounds to 5.12% APY with monthly compounding.

How Fees Affect Short vs Long-Term Borrowing

The same fees have a much larger impact on short-term loans because they are spread over fewer payments:

Loan Term	Rate	$4,000 in Fees	APR	Rate-APR Gap
5 years	6.00%	$4,000	6.68%	0.68%
10 years	6.00%	$4,000	6.36%	0.36%
15 years	6.00%	$4,000	6.25%	0.25%
30 years	6.00%	$4,000	6.13%	0.13%

On a 5-year loan, $4,000 in fees adds 0.68% to the effective rate. On a 30-year mortgage, the same fees add only 0.13%. This is why fees matter more for short-term borrowing and why "no-fee" options are more attractive for people who might refinance or move within a few years.

Discount Points: Buying Down the Rate

A "point" costs 1% of the loan amount and typically lowers the rate by 0.25%. Is it worth it?

Example: $300,000 loan, 30 years. Option A: 6.5% with no points. Option B: 6.25% with 1 point ($3,000).

• Option A payment: $1,896/month
• Option B payment: $1,847/month
• Monthly savings: $49
• Break-even: $3,000 / $49 = 61 months (about 5 years)

If you keep the loan longer than 5 years, the point pays for itself. If you sell or refinance sooner, you lose money on the deal. Use this calculator to compare the APR of both options.

APR on Different Loan Types

APR behaves differently depending on the product. A typical UK personal loan APR is close to the headline rate because origination fees are rare, while a US mortgage APR often sits 0.1-0.3% above the note rate once origination, points, and prepaid interest are added. According to Bankrate's March 2026 national survey, the average 30-year fixed mortgage rate was 6.82% and the corresponding APR was 6.91%, a 0.09% gap that reflects lender fees. Credit card APR is different again - it is a simple annualised rate with no fees rolled in, but issuers compound interest daily, so the effective cost is higher than the stated APR.

For auto loans, fees are usually small and the APR tracks the rate closely. The Federal Reserve's G.19 consumer credit release shows the average 60-month new-car loan APR at 7.55% for Q1 2026 (June 2026 release). For payday loans, the APR is famously high because small fees get spread over short terms: a $15 fee on a $100 loan for two weeks works out to an APR of 391%. This is the same mathematical quirk shown in the short-term loan table above, just taken to an extreme.

Representative APR vs Personal APR (UK)

UK lenders advertise a "representative APR" that must be offered to at least 51% of accepted applicants under Financial Conduct Authority CONC 3.5 rules. The other 49% can be given a higher personal APR based on their credit profile. Experian's 2025 data shows the average personal loan applicant with a "Good" credit score (881-960 on the Experian scale) was offered 11.4% APR, while those with a "Fair" score (721-880) averaged 21.7% APR for the same product advertised at 6.9% representative.

Always check the APR on your actual offer rather than assuming you will get the advertised rate. If you are rejected or offered a worse rate, most lenders will tell you which score band you fell into if you ask.

Common Mistakes When Comparing APRs

• Ignoring the term. A 5-year loan at 7% APR is cheaper than a 30-year loan at 6% APR in total interest, even though the APR is higher.
• Comparing APR to APY. These are not the same. APR excludes compounding; APY includes it. A 6% APR credit card with daily compounding has an APY closer to 6.18%.
• Assuming all fees are included. Some lenders legally exclude optional fees (rate-lock fees, float-down fees, document prep) from the APR calculation. Ask for the Loan Estimate disclosure (US) or the pre-contract credit information (UK) and check the fee breakdown.
• Using APR to compare variable and fixed loans. APR on a variable-rate loan assumes the starting rate holds for the full term, which is rarely true. For adjustable-rate mortgages, also look at the fully-indexed rate.
• Ignoring prepayment plans. APR assumes you hold the loan for the full term. If you plan to pay off early, a loan with higher fees and a lower rate will be worse than the APR suggests.

APR and the Truth in Lending Act

In the US, Regulation Z (12 CFR Part 1026) requires lenders to disclose APR on a standardised Loan Estimate form within three business days of application. The APR box must be at least as prominent as the interest rate itself. For mortgages, the Consumer Financial Protection Bureau defines which fees must be included: finance charges, prepaid interest, origination fees, points, and PMI. Non-finance charges like title insurance (in most states), appraisal, and inspection are excluded.

In the UK, the Consumer Credit Act 1974 and the FCA's CONC rules require the APR to be shown in all credit advertising. For regulated mortgages, the MCD (Mortgage Credit Directive) introduced the APRC (Annual Percentage Rate of Charge), which assumes the current rate holds for the whole term and includes all compulsory fees. The APRC often appears higher than the advertised rate because it reflects the revert-to-SVR rate after the fixed period.

When the Lowest APR Is Not the Best Deal

APR is a useful shortcut, but it is not a complete picture. Two scenarios where chasing the lowest APR can cost you more:

• Short holding period. APR spreads upfront fees across the full loan term. If you refinance or sell before the break-even point (see the discount points example above), the fees never fully amortise. On a 30-year mortgage held for 4 years, a loan with a 6.1% APR and $9,000 in fees will almost always cost more than a loan at 6.4% APR with $1,500 in fees.
• Different loan structures. APR assumes standard monthly amortisation. Interest-only loans, balloon mortgages, and negative-amortisation products have APRs that look reasonable but mask large back-end payments. Always look at the total amount paid over the life of the loan as a second check.
• Teaser rates. A 2-year introductory rate of 3.99% on a credit card that jumps to 22.99% after the teaser ends has a representative APR far closer to 22.99% than to 3.99%. The FCA and CFPB both require lenders to disclose the post-teaser rate, but it is easy to miss.

The total cost field in this calculator strips away these pitfalls by showing the actual dollar amount you will pay over the life of the loan, including fees. When APRs are close (within 0.1%), compare total cost instead. Pair this tool with the loan calculator to see how a change in term changes both APR and total interest.

For monthly payment estimates, the mortgage calculator handles standard mortgages. To see a full payment schedule, the amortization calculator shows every payment split between principal and interest. To work backwards from a payment to find the rate, use the interest rate calculator.

All calculations run locally in your browser. No data is sent anywhere.

Sources

• CFPB - Interest Rate vs APR
• Federal Reserve G.19 Consumer Credit Release
• Bankrate - Mortgage Rates
• FCA Handbook CONC 3.5 - Representative APR
• eCFR - Regulation Z (Truth in Lending)
• GOV.UK - Consumer Credit Act 1974