Two lenders can quote you the same interest rate while one loan quietly costs thousands more. The difference lives in the fees, and the Annual Percentage Rate is supposed to be the great equalizer that exposes it. A loan with a 6 percent note rate and $12,000 of lender fees is not the same deal as a loan with a 6 percent note rate and no fees at all, even though both produce the same monthly payment. APR exists so you can compare those two offers with one number instead of reading two fee schedules line by line. This page explains what APR really means, what this calculator actually computes, and how to use both without being misled by either.

What APR is, and what it is not.

The interest rate, often called the note rate, is the price of borrowing the principal. It is the rate your monthly payment is calculated from. APR starts with that rate and adds the lender charges required to get the loan, then expresses the whole cost as a yearly percentage. That is why APR is almost always higher than the note rate on a real loan disclosure: every fee folded in pushes it up, and a loan with no fees at all has an APR equal to its note rate. What APR is not is a second payment rate. Your servicer never multiplies your balance by the APR to set your payment. The payment comes from the note rate, the balance, and the term. APR is a comparison number, a disclosure number, and it only does its job when you compare APR to APR on loans with the same term and the same structure.

What this calculator actually computes, honestly stated.

This calculator works backward from four numbers you already know: your Loan Amount, Total Fees, Loan Term in months, and Monthly Payment. It totals everything you will ever pay, subtracts the loan amount, adds the fees back in its Total Interest and Fees figure, and annualizes the result with a simple formula: total interest and fees, divided by the loan amount plus fees, divided by the term in years. That is a useful rough check on total cost, but it is not the APR on your Loan Estimate. The disclosure APR under Regulation Z is solved as an internal rate of return, the rate that makes the present value of all your payments equal to the amount you actually receive after fees. The simple formula here spreads cost evenly across the years, which understates the true rate on a long loan, and it has a stranger flaw: because fees sit in the denominator, adding fees to this calculator lowers its APR output. That is the opposite of how a real APR behaves, so never rank lenders by this calculator's APR alone. Rank them by their disclosed APRs, and use this tool to check the dollar totals behind any offer.

Worked example one: the calculator's own defaults.

Enter a $200,000 loan, $3,000 in fees, a 360-month term, and a $1,200 monthly payment. This calculator returns an APR of 3.810 percent, a Total Loan Cost of $432,000, and Total Interest and Fees of $235,000. Check the arithmetic: $1,200 times 360 months is $432,000 of total payments. Subtract the $200,000 loan and you get $232,000 of interest; add the $3,000 of fees and you get $235,000, exactly the figure shown. The APR figure comes from $235,000 divided by $203,000, divided by 30 years, which is 3.810 percent. Now compare that with the true economics of the same loan. A $1,200 payment on a $200,000 loan over 360 months implies a note rate of about 6.007 percent. If you actually receive only $197,000 after the $3,000 of fees, the true APR solved as an internal rate of return is about 6.149 percent. The gap between 3.810 percent and 6.149 percent is not a rounding difference. It is the difference between a simple average and a time-value calculation, and it is why the Loan Estimate number, not this page's estimate, is the one to shop with.

Worked example two: a five-year auto loan.

Enter a $25,000 loan, $500 in fees, a 60-month term, and a $500 monthly payment. This calculator returns an APR of 3.922 percent, a Total Loan Cost of $30,000, and Total Interest and Fees of $5,500. Again the dollars check out: $500 times 60 is $30,000, minus $25,000 is $5,000 of interest, plus $500 of fees is $5,500. The implied note rate behind a $500 payment on $25,000 over 60 months is about 7.420 percent, and the true APR on the $24,500 actually received is about 8.275 percent. The pattern repeats: the simple formula understates the true rate, and the understatement shrinks as the term shortens, because spreading cost over five years distorts less than spreading it over thirty. For short loans this calculator's estimate is closer to reality. For a thirty-year mortgage it is far away, and that distance matters most exactly where the dollars are biggest.

Worked example three: a three-year personal loan.

Enter a $10,000 loan, $200 in fees, a 36-month term, and a $320 monthly payment. This calculator returns an APR of 4.967 percent, a Total Loan Cost of $11,520, and Total Interest and Fees of $1,720. The dollars again check out: $320 times 36 is $11,520, minus $10,000 is $1,520 of interest, plus $200 of fees is $1,720. The implied note rate is about 9.429 percent, and the true APR on $9,800 received is about 10.819 percent. Notice how the fee effect grows as the loan shrinks: $200 of fees on a $10,000 loan moves the true APR by almost 1.4 percentage points, while $3,000 of fees on a $200,000 loan moved it by only about 0.14 points. Small loans punish fees hardest, which is why a personal loan with a 10 percent origination fee can look cheap on its note rate and expensive on its APR, and why fee-heavy small loans deserve the closest reading of all.

The same payment, three different fee loads.

Take a $300,000 loan over 360 months with a $1,896.20 monthly payment, the payment a 6.5 percent note rate produces. With no fees, this calculator shows 4.251 percent. Add $6,000 of fees and it shows 4.168 percent. Add $12,000 of fees and it shows 4.088 percent. The calculator's APR falls as fees rise, which is backwards. The true APRs for those three cases run the other way: 6.500 percent with no fees, about 6.695 percent with $6,000 of fees, and about 6.897 percent with $12,000 of fees. This is the clearest possible demonstration of the tool's limit, and it is worth running yourself before you trust any single number on this page. The Total Interest and Fees figures, by contrast, do move the right way: $382,632 with no fees, $388,632 with $6,000 of fees, and $394,632 with $12,000 of fees. When this calculator disagrees with a lender's disclosure, believe the disclosure's APR and use this calculator's dollar totals to understand what you are paying in total.

Which fees count in a real APR, and which do not.

On a mortgage disclosure, the APR generally includes the interest rate, origination fees, discount points paid to buy the rate down, mortgage broker fees, and mortgage insurance premiums where they apply. It generally does not include third-party charges you would pay with or without a loan, such as appraisal fees, title insurance, attorney fees, home inspection costs, credit report fees, notary fees, transfer taxes, or the property taxes and homeowners insurance held in escrow. That exclusion is why a disclosed APR can still understate your all-in cost slightly, and why the Loan Estimate's cash-to-close and total-of-payments figures deserve a read alongside the APR. For a personal loan, the APR usually includes the interest rate plus any origination or administrative fee, and origination fees on personal loans commonly run from about 1 percent to over 10 percent of the loan amount, often deducted from the funds you receive. For a credit card, the APR and the interest rate are usually the same number, because cards generally charge no origination fee; the APR is simply the yearly rate, with monthly interest roughly equal to the balance times the APR divided by twelve.

How to shop with APR instead of being shopped by it.

First, compare APR to APR, never APR to note rate, and only across loans with the same term: a 15-year APR and a 30-year APR are not rivals, because fees spread over fewer years always look larger. Second, read the gap between note rate and APR as a fee meter. On a mortgage, a gap of roughly 0.1 to 0.5 percentage points is ordinary; a gap far above that means the lender is loading the loan with fees or points, and you should ask for the fee breakdown in writing. Third, remember that APR assumes you keep the loan for its full term. If you refinance or sell after five years, the fees you paid up front were spread over five years, not thirty, so your effective cost was higher than the APR suggested, and a low-APR loan bought with heavy points can lose to a no-points loan on a short hold. Fourth, never let a low APR override the monthly payment: a 15-year loan usually shows a lower APR than a 30-year loan on the same house, but its payment can be hundreds of dollars higher, and a payment you cannot comfortably make is not a bargain at any APR. Finally, treat any APR that differs sharply between this calculator and a lender's disclosure as a question, not an accusation: ask the lender to walk every fee line, and check whether the payment you entered here matches the payment on their estimate, because a mismatched payment moves every output on this page.

APY, variable APR, and the traps that look like APR.

APY, or annual percentage yield, is the savings-account cousin of APR: it includes compounding, so it is the number that tells you what a deposit actually earns over a year. Do not compare a loan's APR with a savings account's APY as if they were the same race. A variable-rate loan's APR is quoted at today's rate and can move with its index, so the APR on an adjustable-rate mortgage is a snapshot, not a promise; ask for the margin, the index, the caps, and the worst-case payment, not just the opening APR. A 0 percent introductory APR on a credit card is a different animal again: it is a promotional rate with an end date, a transfer fee, and a revert rate, and the only APR that matters is the one that applies after the promotion ends if the balance is still there. And a loan advertised by its interest rate alone, with the APR buried in fine print, is telling you where its fees are hiding. The APR exists because Congress decided, in the Truth in Lending Act, that borrowers deserve one comparable number. Use it that way: demand it, compare it like with like, and then verify it against the dollars.

How to use this calculator well.

Enter the loan amount you actually borrow, not the purchase price, and enter every lender fee you know about, including points and origination charges, in Total Fees. Set the term in months exactly as the offer states, 360 for a thirty-year mortgage and 60 for a five-year auto loan, and enter the monthly payment from the lender's quote, not a payment you guessed. Read the Total Loan Cost and Total Interest and Fees first, because those dollar figures are this calculator's honest output, then read the APR estimate with the warning above in mind. Re-run the same payment with the fees set to zero to see how much of the total cost is fees rather than interest. Then put this page aside and compare the lenders' disclosed APRs on their Loan Estimates, same term, same loan amount, and pick the offer whose total cost and monthly payment both fit your life, not merely the one with the smallest advertised percentage.

With the pre-filled defaults — Loan Amount $200,000, Total Fees $3,000, Loan Term (Months) 360, Monthly Payment $1,200 — the APR Calculator returns APR (Estimated) 3.810%, Total Loan Cost $432,000.00, Total Interest & Fees $235,000.00. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.