Methodology

How we calculate the differences between offers.

What is compared

Conventional, fixed-rate, fully amortizing purchase loans for the same property and transaction. Cost ranking requires equal loan amount and equal term. Anything else is shown for reference or explained, never ranked.

How numbers are produced

• All arithmetic is deterministic and uses exact decimal math, not floating point.
• Financial calculations do not use AI or OCR. Photos use on-device text recognition to suggest values; you must check and confirm them before calculation.
• The screen displays results from the calculation engine. It never recomputes them.
• Unknown values are never treated as zero. They block the metric that depends on them.

Measures

• Net upfront financing cost: confirmed borrower-paid, nonfinanced borrowing charges, including those already paid before closing, minus confirmed usable lender credit. A negative subtotal is not promised cash back.
• Monthly payment: principal and interest for the stated rate and term.
• Modeled financing cost at a horizon: net upfront financing cost plus scheduled interest and confirmed mortgage insurance through exactly that many monthly payments.

What is not included

Principal repaid, down payment, property taxes, homeowners insurance, ownership transaction costs, and escrow reserve transfers are excluded. Loan-related services in Sections A, B, and C, prepaid borrowing interest, and upfront mortgage insurance are included. There is no composite score and no single best offer.

Fee policy, version 1

• A: origination charges and points — included once.
• B: required lender-selected services — included, not necessarily lender revenue.
• C: shoppable services — included as quoted; differences are conditional until confirmed or consistently normalized.
• D, I, J: subtotals — reconciliation only, not counted twice.
• E: government transaction charges — cash budgeting, not financing ranking.
• F: prepaid interest and upfront mortgage insurance — included; taxes and homeowners insurance — excluded.
• G: escrow reserves — cash transfers, excluded.
• H: ownership transaction items — excluded by default; unusual borrowing fees need explicit classification.
• Lender credits: only the confirmed usable amount is subtracted, once. Seller credits and grants are not lender credits.

Rounding and assumptions

The analytical model uses 50 significant digits, an explicit final payment that closes the balance, and half-up currency display rounding. It uses the note interest rate and 0% discounting. It does not predict refinancing, rate changes, appreciation, tax benefits, or investment returns. A one-cent tolerance identifies practical modeled ties; a $250 close-result cue does not establish economic certainty or legal materiality.