Financing guide

How to compare two mortgage proposals

Build one table for rate, CET, index, costs, initial payment and estimated total across two proposals.

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Updated August 31, 2026

In this guide
  1. Normalize proposals
  2. Comparison table
  3. Interpret without shortcuts

Normalize proposals

Compare the same property value, down payment, principal and term. Record interest, annual rate type, system, index, CET, insurance, fees, first due date and prepayment rules separately.

Comparison table

Field Proposal A Proposal B
Principal and term equal equal
Interest BCB fixed-rate median BCB TR-indexed median
Adjustment none repeated TR reference
Hypothetical monthly cost BRL 0 BRL 120
CET check document check document

BCB references for 2026-07: median of 3 fixed-rate and 13 TR-indexed institutions.
TR reference: 0.1760% monthly, observation dated October 7, 2025, repeated only as an estimate.

Parameters used

Financed amount
R$300,000.00
Term
360 months
Interest rate
14.9797% effective per year
System
SAC
Monthly adjustment
—
Extra amortization
—

Calculated results

ScenarioProposal A: fixed rateProposal B: TR and costs
First paymentR$4,343.33R$3,809.82
Last paymentR$844.29R$1,704.36
Total interestR$633,557.33R$643,356.93
Total paidR$933,557.33R$1,105,537.81
Effective term360 months360 months
Accumulated adjustmentR$0.00R$118,980.88

Selected installments

Payment no.PaymentInterestAmortizationClosing balance
1R$4,343.33R$3,510.00R$833.33R$299,166.67
12R$4,236.08R$3,402.75R$833.33R$290,000.04
60R$3,768.08R$2,934.75R$833.33R$250,000.20
180R$2,598.09R$1,764.76R$833.33R$150,000.60
360R$844.29R$9.76R$834.53R$0.00
Outstanding balance over timeProposal A: fixed rate / Proposal B: TR and costs
Outstanding balance over timeProposal A: fixed rateProposal B: TR and costs
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Interpret without shortcuts

comparable cost = payments + initial expenses + ancillary costs

A lower first payment may come with indexation, a longer term or another charge. An estimated total also does not replace CET: they are different measures.

What may differ in a contract

  • A proposal and final contract may have different validity, approval conditions and costs; compare the same stage.
  • Indexes, insurance and fees may change over time and require explicit rules.

Limits of this analysis

  • The scenario uses hypothetical proposals and does not recommend a lender or product.
  • Future totals with repeated TR are estimates, not guarantees.

Sources and review