Understanding your APR result
The table below shows the general relationship between fees and the gap between APR and the note rate, holding the loan amount, note rate and term constant.
| Upfront fees (on $200,000, 6%, 30-yr) | Approx. APR | Gap vs. 6% note rate |
|---|---|---|
| $0 | 6.000% | 0.000 pts — APR equals note rate with no fees |
| $2,000 | ≈ 6.094% | ≈ 0.09 pts |
| $4,000 | 6.189% (exact) | 0.189 pts |
| $8,000 | ≈ 6.383% | ≈ 0.38 pts |
- APR always equals or exceeds the note rate when fees are financed into the calculation, and equals the note rate only when there are no included fees.
- The specific fees a lender includes in its APR disclosure are governed by Regulation Z and vary somewhat by fee type; this calculator uses whatever total fee figure is entered and does not itemize which individual charges a specific lender would include.
- APR is most reliable for comparing loans of the same type and term; comparing a 15-year APR against a 30-year APR, or a fixed-rate APR against an adjustable-rate APR, can be misleading because fee impact and rate-change risk differ structurally.
What is APR?
The annual percentage rate is a standardized cost-of-credit figure that the Truth in Lending Act (implemented through the CFPB's Regulation Z) requires lenders to disclose. Unlike the note rate, which is used only to calculate the monthly payment, the APR incorporates certain upfront finance charges — such as points, origination fees and some closing costs — spread over the life of the loan, so it is always equal to or higher than the note rate whenever fees are charged.
The APR is calculated by finding the interest rate that, if applied to the loan amount minus the fees being financed, would produce the exact same monthly payment as the actual loan (principal at the note rate). This makes the APR a way to compare loans with different combinations of rate and fees on a like-for-like annualized basis.
The CFPB notes that APR is most useful for comparing loans of the same type and term; it is a less reliable comparison tool across loans with very different terms, because the same fee amortized over a longer term produces a smaller APR impact than the identical fee on a shorter loan.
How to use this APR calculator
- Enter the loan amount you are borrowing.
- Enter the stated (note) interest rate offered for the loan.
- Enter the total upfront fees being financed into the cost of the loan — points, origination fees, and applicable closing costs the lender includes in its APR disclosure.
- Enter the loan term in years.
- Read the calculated APR, compare it with the stated note rate, and review the monthly payment and total fee amount used in the calculation.
The formula behind APR
The monthly payment is first calculated using the standard amortization formula on the full loan amount at the stated note rate. The APR is then found by solving for the monthly rate that discounts that same payment stream down to a present value equal to the loan amount minus the fees — effectively asking, 'what rate would produce this payment if I had only received the amount after fees?' Because there is no closed-form algebraic solution, the rate is found by iterative numerical search (bisection) until the discounted payment stream matches the after-fee amount.
Worked example: a $200,000 loan at a 6% note rate with $4,000 in upfront fees over a 30-year term has a monthly payment of $1,199.10 (based on the full $200,000 at 6%). Solving for the rate that discounts that same $1,199.10 payment stream to $196,000 (the amount after fees) over 360 months gives an APR of 6.189% — higher than the 6% note rate because the fees are being repaid within the same monthly payment.
Common mistakes
- Comparing the APR of loans with different terms and assuming the lower APR is automatically the cheaper loan — term length changes how much fee-amortization affects the APR.
- Confusing APR with the note rate used to calculate the monthly payment; the monthly payment in this calculator is based on the note rate, not the APR.
- Omitting fees the lender will actually charge, which understates the calculated APR relative to the lender's own disclosure.
- Assuming APR captures every cost of homeownership — it reflects only certain financing charges, not property taxes, insurance, HOA dues or costs unrelated to the loan itself.
- Treating a small APR difference as immaterial without considering the loan amount and term — even a fraction of a percentage point compounds meaningfully over a 30-year term.
よくある質問
What is the difference between APR and interest rate?
The interest (note) rate is used to calculate the loan's monthly principal-and-interest payment. The APR incorporates that rate plus certain upfront finance charges — such as points, origination fees and some closing costs — expressed as an equivalent yearly rate, so it is typically higher than the note rate whenever fees are financed into the loan.
Why is my APR higher than my interest rate?
APR is higher than the note rate whenever the lender charges upfront fees that are included in the APR disclosure, because those fees are effectively being repaid within the same monthly payment stream calculated at the note rate — spreading a smaller net amount received (loan minus fees) across the same payments produces a higher implied annual rate. For example, a $200,000 loan at 6% with $4,000 in fees has an APR of 6.189%.
Is a lower APR always the better loan?
Not necessarily across different loan structures. APR is most useful for comparing loans of the same type and term, since the same dollar amount of fees has a smaller proportional effect on APR over a longer term. Comparing a short-term loan's APR against a long-term loan's APR, or a fixed-rate APR against an adjustable-rate APR, requires additional context beyond the single APR figure.
Does APR include property taxes and insurance?
No. APR under Truth in Lending / Regulation Z disclosure rules covers certain finance charges related to obtaining the credit itself — such as points, origination fees and some closing costs — not property taxes, homeowners insurance, HOA dues, or other costs of owning the property that are unrelated to the financing.
How is APR calculated?
APR is found by determining the interest rate that would make the loan's actual monthly payment (calculated at the note rate on the full loan amount) equal to the payment on a smaller amount — the loan amount minus the fees being financed — over the same term. Because this has no simple algebraic solution, lenders and calculators solve for it numerically; the result is always expressed as an annualized percentage.
参考文献
- Consumer Financial Protection Bureau (CFPB). What is the difference between a mortgage interest rate and an APR? consumerfinance.gov.
- Consumer Financial Protection Bureau (CFPB). Truth in Lending Act / Regulation Z disclosure requirements. consumerfinance.gov.
- Federal Reserve Board. A consumer's guide to mortgage refinancing. federalreserve.gov.
- Freddie Mac. Understanding mortgage options and loan types. freddiemac.com.
- Brueggeman WB, Fisher JD. Real Estate Finance and Investments. 15th ed. McGraw-Hill Education, 2019.