Why does the APR not match what my lender disclosed?

A few possibilities. (1) Reg Z permits a ±0.125% tolerance on regular (fully-amortizing, equal-payment) loans and ±0.25% on irregular loans — small disagreements within these bounds are normal. (2) Some lenders use a "U.S. Rule" 365-day method while this calculator uses the actuarial method most commonly used for closed-end mortgages. (3) The disclosed APR may include some fees this calculator does not, or vice versa — check the itemization on your Loan Estimate Page 3 / Closing Disclosure Page 5.

Should I always pick the loan with the lowest APR?

No — APR optimizes for a borrower who keeps the loan its full term. If you will refinance or sell within 5 years, a higher-rate loan with lower fees often wins because the prepaid points never amortize. Always look at total finance charge over your expected holding period, not just APR. CFPB's "Owning a Home" tools include a 5-year cost comparison alongside APR for exactly this reason.

Why is the APR on credit cards so much higher than mortgages?

Credit-card APRs (often 18-29%) are quoted without the upfront-fee adjustment used for closed-end credit — there is no upfront amount-financed step on a revolving line. They are also unsecured and short-duration, both of which command a risk premium. Reg Z still requires APR disclosure but applies a "purchase APR" / "cash advance APR" / "penalty APR" structure rather than the single-figure actuarial method used for installment loans.

Does APR include mortgage insurance?

Yes, for closed-end consumer mortgages with private mortgage insurance, FHA MIP, or VA funding fees — these are finance charges under Reg Z §1026.4. Up-front MIP/funding fees are included in the prepaid finance charge total; monthly MIP/PMI premiums are added to the scheduled payment stream the APR calculation uses. This is one of the largest reasons FHA loan APRs typically run 0.5-1.0 percentage points above the note rate.

Why does the APR not match what my lender disclosed?

A few possibilities. (1) Reg Z permits a ±0.125% tolerance on regular (fully-amortizing, equal-payment) loans and ±0.25% on irregular loans — small disagreements within these bounds are normal. (2) Some lenders use a "U.S. Rule" 365-day method while this calculator uses the actuarial method most commonly used for closed-end mortgages. (3) The disclosed APR may include some fees this calculator does not, or vice versa — check the itemization on your Loan Estimate Page 3 / Closing Disclosure Page 5.

Should I always pick the loan with the lowest APR?

No — APR optimizes for a borrower who keeps the loan its full term. If you will refinance or sell within 5 years, a higher-rate loan with lower fees often wins because the prepaid points never amortize. Always look at total finance charge over your expected holding period, not just APR. CFPB's "Owning a Home" tools include a 5-year cost comparison alongside APR for exactly this reason.

Why is the APR on credit cards so much higher than mortgages?

Credit-card APRs (often 18-29%) are quoted without the upfront-fee adjustment used for closed-end credit — there is no upfront amount-financed step on a revolving line. They are also unsecured and short-duration, both of which command a risk premium. Reg Z still requires APR disclosure but applies a "purchase APR" / "cash advance APR" / "penalty APR" structure rather than the single-figure actuarial method used for installment loans.

Does APR include mortgage insurance?

Yes, for closed-end consumer mortgages with private mortgage insurance, FHA MIP, or VA funding fees — these are finance charges under Reg Z §1026.4. Up-front MIP/funding fees are included in the prepaid finance charge total; monthly MIP/PMI premiums are added to the scheduled payment stream the APR calculation uses. This is one of the largest reasons FHA loan APRs typically run 0.5-1.0 percentage points above the note rate.

APR Calculator

True Annual Percentage Rate (Reg Z / Truth in Lending) — nominal rate plus fees rolled into one comparable figure.

Result

Effective APR (Reg Z)

6.676%

0.176% above the quoted 6.500% nominal rate

Quoted nominal rate6.500%
Upfront fees / points$4,500.00
Net amount advancedprincipal minus upfront finance charges$245,500.00
Payment per month$1,580.17
Total of payments$568,861.22
Total finance chargeinterest + fees over loan life$323,361.22
APR − note ratefee drag on effective rate0.176%

Moderate fee drag

Effective APR

6.676%

Quoted "note rate"

before fees

6.500%

Total finance charge

$323,361.22

Fee drag (APR − rate)

Reg Z requires this disclosure within ±0.125% on standard mortgages

0.176%

CFPB tolerance for accurate disclosure

12 CFR 1026.22(a)(2)-(3)

±0.125% (regular) / ±0.25% (irregular)

Source: Federal Reserve Regulation Z / Truth in Lending Act (12 CFR Part 1026), Appendix J — Actuarial APR method.

Not financial advice — Lenders must disclose APR within Reg Z tolerances on the Loan Estimate and Closing Disclosure. APRs are still imperfect for comparing across products (e.g. adjustable vs fixed, different terms) — always also compare total finance charge and payment schedule.

How to use this calculator

Enter the loan amount (the principal — what shows on the note).
Enter the quoted interest rate (the "note rate", not an existing APR figure).
Set the term (years) and payment frequency.
Add all upfront finance charges — origination, discount points, prepaid finance charges. Skip property taxes, homeowners insurance, and other non-finance settlement charges per Reg Z §1026.4(c).

About this tool

Two rates show up on every loan offer and they almost never match. The "note rate" (or interest rate) is what determines your monthly payment. The APR — Annual Percentage Rate, defined by Federal Reserve Regulation Z under the Truth in Lending Act — rolls upfront finance charges (origination fees, discount points, mortgage insurance premiums on FHA loans, prepaid interest, lender title fees) back into an effective annual rate, so a 6.5% note rate with $4,500 of fees on a $250k 30-year mortgage might disclose as a ~6.66% APR. The APR is the comparison number — Reg Z explicitly designed it for shopping. This calculator runs the actuarial APR method from Reg Z Appendix J: it solves for the rate that makes the present value of all scheduled payments equal to the net amount actually advanced (principal minus upfront finance charges).

What this calculator does

Computes the effective Annual Percentage Rate for a closed-end installment loan using the actuarial method from Federal Reserve Regulation Z, Appendix J. Given the principal, quoted note rate, term, payment frequency, and upfront finance charges, the calculator solves for the rate that makes the present value of the scheduled payments equal to the net amount actually advanced — the same algorithm lenders use on the Loan Estimate and Closing Disclosure.

How it works — the formula

Period payment M = P · r / (1 − (1+r)^−n)
  P = principal (note amount), r = note rate / payments per year, n = total payments

APR per Reg Z Appendix J:
  Find r* such that  M · (1 − (1+r*)^−n) / r*  =  P − upfront finance charges
  Annual APR = r* × payments per year

The note rate determines the periodic payment via the standard amortization formula. The APR then back-solves for the discount rate that makes the present value of those payments equal to the amount actually advanced — principal minus upfront finance charges. With no fees, APR equals the note rate exactly. With fees, APR exceeds the note rate, by an amount proportional to the fee fraction divided by loan duration. Reg Z Appendix J specifies an iterative actuarial method; this calculator implements a bisection solver to roughly 10⁻¹⁰ precision.

Sources: 12 CFR Part 1026 (Regulation Z) — Truth in Lending · Regulation Z Appendix J — Annual Percentage Rate Computations for Closed-End Credit Transactions · CFPB — Loan Estimate explainer and Know Before You Owe rule · Truth in Lending Act (15 USC 1601-1667f)

Worked examples

Example 1

30-year mortgage with 2 points

Inputs:: principal = $250,000; note rate = 6.5%; term = 30 yr monthly; upfront fees = $4,500 (1.8 points)
Output:: Monthly payment = $1,580.17; net advanced = $245,500; APR ≈ 6.661%; APR − rate = +0.161%

A typical 2-point pay-down on a $250k loan adds ~0.16% to the APR — meaningful only if you keep the loan past the break-even (here ~7 years).

Example 2

5-year auto loan with origination fee

Inputs:: principal = $30,000; note rate = 7.99%; term = 5 yr monthly; upfront fees = $400
Output:: Monthly payment = $608.27; net advanced = $29,600; APR ≈ 8.292%

A small upfront fee on a short-duration loan produces a larger relative APR bump than on a 30-year mortgage — duration matters.

Example 3

Loan with no fees (sanity check)

Inputs:: principal = $50,000; note rate = 9%; term = 10 yr monthly; upfront fees = $0
Output:: Monthly payment = $633.38; APR = 9.000% (exact)

With zero finance charges, APR equals the note rate by definition — a useful smoke test for any APR implementation.

When to use this vs other tools

APR is the comparison number for closed-end installment credit. For other loan questions, the sibling tools below are more specific.

Loan Calculator
You want the monthly payment, total interest, and amortization schedule from a known rate — without back-solving for APR.
Mortgage Calculator
You want a full PITI breakdown (principal, interest, taxes, insurance) — APR covers only the finance-charge portion.
Refinance Calculator
You want the break-even month and lifetime savings of refinancing — compare APRs at that level instead of headline rates.
Compound Interest Calculator
You want the saving / earning side (APY-style) instead of the borrowing-cost (APR) side.

Authority note

Federal Reserve / CFPB

Regulation Z (12 CFR Part 1026) — Truth in Lending Act, Appendix J: Annual Percentage Rate Computations for Closed-End Credit Transactions

Reg Z is the implementing regulation for the Truth in Lending Act (15 USC 1601). It defines APR, mandates disclosure on the Loan Estimate and Closing Disclosure (via TRID / Know Before You Owe), and specifies the actuarial computation method used here. CFPB took over administration from the Federal Reserve in 2011.

Limitations

APR assumes you keep the loan to maturity. If you sell, refinance, or pay off early, the real all-in cost can be very different — particularly when discount points are involved.
APR is only directly comparable between loans of the same type, term, and payment structure. An adjustable-rate APR uses the index-plus-margin at origination and may diverge sharply from actual payments later.
Some "finance charges" are at the lender's discretion to classify (e.g. settlement-related fees). Compare itemized Loan Estimate Page 3 / Closing Disclosure Page 5 sections, not just the headline APR.
This calculator handles closed-end installment credit only. Open-end credit (credit cards, HELOCs), reverse mortgages, and loans with negative amortization use different Reg Z disclosure structures.
Reg Z permits ±0.125% tolerance for regular loans and ±0.25% for irregular loans on the disclosed APR. Small disagreements with a lender's disclosure within those bounds are expected.

APR computations are illustrative. This calculator does not provide lending, legal, or tax advice. Reg Z disclosures from your lender are the authoritative figures for any actual loan; consult the official Loan Estimate and Closing Disclosure before signing.

Frequently asked

The interest rate (or "note rate") is what determines your monthly payment via the amortization formula. The APR rolls upfront finance charges into the rate so you can compare loans on a single number. Reg Z (12 CFR Part 1026) defines exactly which fees are "finance charges" and must be included in APR — origination, discount points, mortgage insurance, prepaid interest, lender-required services. Property taxes, homeowner's insurance, and recording fees are NOT finance charges and are excluded from APR.