APR Calculator

How to use this calculator

Five inputs. Fill in all five for the most accurate result.

Loan Amount — The total amount you are borrowing, before any fees are deducted. If your lender charges origination fees and rolls them into the loan, use the gross loan amount. If fees are paid at closing out of pocket, use the loan amount as stated.

Nominal Interest Rate — The stated interest rate on your loan, not the APR. This is the rate your lender quotes for the actual borrowing cost before fees. Enter it as a percentage.

Fees / Closing Costs — All upfront fees associated with getting the loan. For mortgages, this includes origination fees, discount points, processing fees, and underwriting fees. For auto loans, include dealer finance charges and any processing fees. For personal loans, include origination fees. Do not include third-party fees like appraisals, title insurance, or government recording fees, as these are excluded from APR by law.

Loan Term — The repayment period in years. APR is highly sensitive to loan term. The same fees spread over 30 years raise the APR much less than the same fees spread over 3 years.

Loan Type — Select the type of loan for context. The calculation method is the same for all types, but this helps you interpret the result against typical benchmarks for each loan category.

What APR actually measures

The nominal interest rate tells you the cost of borrowing the principal. But getting a loan usually costs more than just the interest. Origination fees, points, mortgage insurance, and processing charges all add to what you actually pay. The nominal rate ignores all of this.

APR solves this by converting the total cost of the loan, including all financing fees, into a single annualized rate. Think of it as the interest rate that would produce the same total cost if there were no separate fees at all.

This makes APR the most meaningful single number for comparing loan offers from different lenders. Two lenders might quote the same 6.5% rate, but one charges $2,000 in origination fees and the other charges $6,000. Their APRs will differ, and the APR tells you which loan actually costs more.

APR is a standardized cost metric required by the Truth in Lending Act (TILA) in the United States. Lenders must disclose APR so borrowers can make fair comparisons. The calculation method is regulated, which means APRs from different lenders are computed the same way and are directly comparable.

How APR is calculated

APR is calculated using the internal rate of return (IRR) method applied to the loan’s cash flows.

The setup: you receive the loan amount minus financing fees on day one (net proceeds). You then make regular payments over the loan term. APR is the annual rate at which the present value of all those future payments equals the net proceeds you actually received.

The iterative formula approach:

1. Calculate the standard monthly payment using the nominal rate
2. Subtract all financing fees from the loan amount to get net proceeds
3. Find the monthly rate r such that: Net Proceeds = Monthly Payment × [(1 − (1+r)^−n) / r]
4. Multiply r by 12 to get the annual APR

This is solved numerically because there is no closed-form algebraic solution. The calculator uses Newton-Raphson iteration, which converges to high accuracy within a few dozen iterations.

For the example: $250,000 loan at 6.5% for 30 years produces a $1,580.17 monthly payment. With $5,000 in fees, net proceeds are $245,000. The monthly rate that makes the PV of 360 payments of $1,580.17 equal $245,000 is 0.5613%, which annualizes to 6.736% APR.

APR benchmarks by loan type

Loan Type	Excellent Credit APR	Good Credit APR	Fair Credit APR
30-year mortgage	6.0-7.0%	7.0-8.5%	8.5-10.0%
15-year mortgage	5.5-6.5%	6.5-7.5%	7.5-9.0%
Auto loan (new, 60 mo)	4.5-6.5%	6.5-9.0%	9.0-15.0%
Personal loan	7.0-12.0%	12.0-20.0%	20.0-30.0%
Credit card	15.0-22.0%	22.0-27.0%	27.0-35.0%

These ranges are approximate and shift with the broader interest rate environment. In a high federal funds rate environment, all categories move upward. The relative differences between credit quality tiers remain fairly stable.

Credit cards are in a category of their own. Even excellent credit cardholders face APRs that would be shocking for secured loans. This reflects the unsecured, revolving nature of credit card debt and the high default rates relative to collateralized loans.

What fees are included in APR (and what are not)

Included in APR:

• Loan origination fees
• Discount points (prepaid interest)
• Mortgage broker fees
• Private mortgage insurance premiums (for mortgages below 80% LTV)
• Underwriting fees
• Application fees (if required to get the loan)
• Dealer finance charges (auto loans)
• Personal loan origination fees

Not included in APR:

• Appraisal fees
• Title insurance and title search fees
• Attorney fees
• Recording fees and transfer taxes
• Home inspection fees
• Homeowners insurance

The distinction matters for mortgage shopping. A lender quoting a very low APR might be excluding certain fees. Ask for a Loan Estimate document, which is legally required to use standardized APR calculations, and compare those documents across lenders rather than relying on advertised APR alone.

APR vs APY for loans

APR is the rate used for loans. APY (Annual Percentage Yield) is the rate used for deposits and investments.

For loans, most use APR. For savings accounts and CDs, institutions advertise APY because it is higher than the underlying rate (compounding makes it look better).

The difference: APR for loans is calculated on a per-period basis (monthly for most loans) but advertised as an annual rate by multiplying by 12. This is a simple sum, not compounded. APY compounds the periodic rate to get the true annual equivalent.

If a credit card has an 18% APR and compounds daily, the effective APY is: (1 + 0.18/365)^365 − 1 = 19.72%. The credit card company advertises 18% APR. The true effective annual cost is 19.72%. This is legal, standard, and widely misunderstood.

For installment loans (mortgages, auto, personal), the practical difference between APR and APY is small because balances decline with each payment. For revolving credit like credit cards, where you might maintain a constant balance, the APY difference becomes meaningful over longer periods.

How loan term affects the APR premium

One of the most counterintuitive aspects of APR is how strongly it depends on loan term.

The same dollar amount of fees creates a much larger APR premium on short-term loans. This is because the fees are effectively amortized over all the payments. Fewer payments means each payment carries a larger share of the fee burden, producing a larger gap between nominal rate and APR.

Example: $250,000 loan at 6.5% with $5,000 in fees

Term	Monthly Payment	APR
5 years	$4,847	7.76%
10 years	$2,832	7.10%
15 years	$2,180	6.88%
20 years	$1,863	6.79%
30 years	$1,580	6.74%

The same $5,000 in fees raises the APR by 1.26 points on a 5-year loan but only 0.24 points on a 30-year loan. This is why comparing APRs only makes sense when loan terms are similar.

A no-fee loan at 6.8% for 15 years has an APR of 6.8%. A 0-point, $4,000-fee loan at 6.5% for 15 years has an APR of 6.72%. In this case, the lower nominal rate loan actually has a lower APR on the longer term. Do the full comparison before assuming the headline rate tells the whole story.

The breakeven analysis for points and fees

Some lenders offer lower interest rates in exchange for paying discount points upfront. One point equals 1% of the loan amount. Paying one point on a $300,000 mortgage costs $3,000 upfront but might reduce the rate from 7.0% to 6.75%.

The breakeven question: how long do you need to keep the loan to recoup that $3,000 in monthly payment savings?

$300,000 at 7.0%: monthly payment = $1,996 $300,000 at 6.75%: monthly payment = $1,946

Monthly savings = $50. Breakeven = $3,000 / $50 = 60 months (5 years).

If you plan to stay in the home and keep the loan for more than 5 years, buying the point saves money. If you might sell or refinance in under 5 years, do not buy the point.

The APR of each option captures this trade-off automatically. The loan with points will have a lower APR over the full 30 years but a higher APR if you calculate it over 5 years. Using the full-term APR to compare point vs no-point options only makes sense if you genuinely plan to hold the loan to maturity.

The bottom line

APR is the right number to compare loan offers from different lenders, as long as you compare loans of the same type and similar term.

It is not the right number to use in isolation. Check the Loan Estimate, not just the advertised APR. Ask your lender which fees are included. Understand whether the APR calculation matches your intended holding period. And recognize that APR is a snapshot: on adjustable-rate loans, the APR changes when the rate adjusts.

For fixed-rate loans where you plan to hold to maturity, APR is close to a complete picture. For everything else, it is a useful starting point that requires context to interpret correctly.