Bank Contract Review Calculator (Brazil)

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Brazil Bank Interest Rate Review vs Central Bank Average

Brazilian Bank Interest Review: Comparing Contract Rates to the Central Bank Average

A Brazilian bank loan interest rate is not automatically abusive just because it feels high: the parameter Superior Tribunal de Justiça case law relies on most often is a comparison with the average market rate the Central Bank itself publishes for each credit type. This calculator compares the contracted rate with the BACEN average rate the user provides and recalculates the installment using the Price or SAC amortization system as if the average rate applied instead; this guide explains the comparison mechanism and why no single fixed percentage defines abusiveness on its own.

The BACEN average as a yardstick, not an automatic verdict

The starting point of the comparison is simple: the calculator divides the monthly contract rate by the Central Bank's monthly average rate to get the ratio between the two, and it also computes the difference in percentage points. A 12% monthly contract rate against a 6% monthly average rate results in a ratio of 2 times the average, for example; that ratio is the central figure guiding the analysis, because STJ case law, starting with REsp 1.061.530, treats the Central Bank's own average rate, published per credit type under Resolução CMN 4.557/2017, as the comparison parameter, rather than any fixed interest cap.
When the contract rate is above the average, the calculator recalculates the installment as if the rate were the BACEN average, using whichever amortization system is chosen: under the Price system, the recalculated installment stays fixed from the first month to the last, using the standard amortization formula with decreasing interest on the outstanding balance; under the SAC system, the monthly amortization stays constant and the recalculated installment decreases month by month, so the tool shows both the first installment, the highest, and the last, the lowest, of the new schedule. The amortization system used in the recalculation should match the one the original contract actually used, because comparing a Price recalculation against a SAC original produces an estimated savings figure that does not match what the contract really provided.
The real trap is treating any ratio above 1.0 times the average, or even the 1.5 times threshold frequently referenced in rulings such as REsp 271.214/RS, REsp 1.036.818 and REsp 971.853/RS, as automatic proof of abusiveness. None of these percentages is a fixed or binding criterion: the final characterization of abusiveness, under CDC Article 51, IV and Civil Code Article 413, depends on the specifics of each case, including the credit type, the timing of the contract and other contractual elements a calculator does not evaluate. The tool flags the indication through the ratio between the rates; it does not decide abusiveness and it does not estimate the odds of winning a review lawsuit.

Three contract rates, three different readings

Contract rate 2 times the BACEN average (Price system)

Input: R$ 10.000,00 financiados em 12 parcelas de R$ 1.614,35 (taxa contratual de 12% ao mês) contra uma taxa média BACEN hipotética de 6% ao mês
Expected output: Razão de 2,00 vezes a taxa média; parcela recalculada pelo Price cai para R$ 1.192,77; economia total estimada de R$ 5.058,96 no contrato

A ratio of 2 times the average, above the 1.5 times threshold frequently cited by case law (as in REsp 1.061.530), is treated by the tool as an indication of manifest abusiveness, but the final characterization still depends on a judge's review of the specific case.

Contract rate below the BACEN average

Input: Taxa contratual de 5% ao mês contra uma taxa média BACEN hipotética de 6% ao mês, mesma modalidade
Expected output: Razão de 0,83, diferença de -1 ponto percentual; a ferramenta não aponta indício de abusividade pelo critério da taxa média

When the contracted rate already sits at or below the market average, the BACEN average-rate criterion from REsp 1.061.530 does not support an indication of abusiveness; other contract review grounds, unrelated to this criterion, are not evaluated by this tool.

The same review under the SAC system

Input: O mesmo contrato do exemplo anterior, recalculado pelo sistema SAC em vez do Price
Expected output: Primeira parcela recalculada R$ 1.433,33, última parcela R$ 883,33, total revisado R$ 13.900,00 (economia de R$ 5.472,20 no contrato)

Under SAC, monthly amortization stays constant and interest applies to a shrinking outstanding balance, so the installment decreases month by month; that is why the tool shows the first, highest installment and the last, lowest one, instead of a single fixed value like under Price.

Full tool FAQ

When is a bank interest rate considered abusive?

The STJ does not adopt a fixed percentage. It analyzes whether the rate notoriously diverges from the market average, causing exaggerated disadvantage to the consumer (CDC art. 51, IV).

How to obtain the BACEN average rate?

Is there a statute of limitations for revision actions?

What evidence is needed for a revision lawsuit?

Can paid-off old contracts be revised?

Does being above the BACEN average already make the rate abusive?

How does the tool recompute the revised installment?

Does the calculator prove that the contract is abusive?

Frequently asked questions

Is a bank interest rate above the market average already considered abusive?

Not automatically. The STJ, in REsp 1.061.530, uses the Central Bank average rate as a comparison parameter, but case law usually requires a more significant gap, often referenced as above 1.5 times the average, to recognize an indication of manifest abusiveness; the final characterization always depends on the specific case, under CDC Article 51, IV.

Where can I find the Central Bank average rate to compare with my contract?

The Central Bank publishes the monthly average rate per credit type in its interest rate and banking spread table, at bcb.gov.br/estatisticas/txcred, under Resolução CMN 4.557/2017; it is the rate for the contract's signing month that should be entered in the comparison.

What is the difference between reviewing an installment under Price versus SAC?

Under Price, the recalculated installment stays fixed from start to finish; under SAC, monthly amortization stays constant and interest applies to a shrinking balance, so the recalculated installment starts higher and ends lower. The system used in the review should match the one the original contract used, for the comparison to make sense.

Does this calculator decide whether my contract has abusive interest?

No. It compares the contracted rate with the BACEN average rate entered and shows the ratio between the two as an indication, following the parameter from STJ's REsp 1.061.530; the final abusiveness of a specific contract is only recognized in a court ruling, after reviewing the particulars of the case.

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Brazil Bank Interest Rate Review vs Central Bank Average

Brazilian Bank Interest Review: Comparing Contract Rates to the Central Bank Average

The BACEN average as a yardstick, not an automatic verdict

The starting point of the comparison is simple: the calculator divides the monthly contract rate by the Central Bank's monthly average rate to get the ratio between the two, and it also computes the difference in percentage points. A 12% monthly contract rate against a 6% monthly average rate results in a ratio of 2 times the average, for example; that ratio is the central figure guiding the analysis, because STJ case law, starting with REsp 1.061.530, treats the Central Bank's own average rate, published per credit type under Resolução CMN 4.557/2017, as the comparison parameter, rather than any fixed interest cap.

When the contract rate is above the average, the calculator recalculates the installment as if the rate were the BACEN average, using whichever amortization system is chosen: under the Price system, the recalculated installment stays fixed from the first month to the last, using the standard amortization formula with decreasing interest on the outstanding balance; under the SAC system, the monthly amortization stays constant and the recalculated installment decreases month by month, so the tool shows both the first installment, the highest, and the last, the lowest, of the new schedule. The amortization system used in the recalculation should match the one the original contract actually used, because comparing a Price recalculation against a SAC original produces an estimated savings figure that does not match what the contract really provided.

The real trap is treating any ratio above 1.0 times the average, or even the 1.5 times threshold frequently referenced in rulings such as REsp 271.214/RS, REsp 1.036.818 and REsp 971.853/RS, as automatic proof of abusiveness. None of these percentages is a fixed or binding criterion: the final characterization of abusiveness, under CDC Article 51, IV and Civil Code Article 413, depends on the specifics of each case, including the credit type, the timing of the contract and other contractual elements a calculator does not evaluate. The tool flags the indication through the ratio between the rates; it does not decide abusiveness and it does not estimate the odds of winning a review lawsuit.

Three contract rates, three different readings

Contract rate 2 times the BACEN average (Price system)

Input: R$ 10.000,00 financiados em 12 parcelas de R$ 1.614,35 (taxa contratual de 12% ao mês) contra uma taxa média BACEN hipotética de 6% ao mês
Expected output: Razão de 2,00 vezes a taxa média; parcela recalculada pelo Price cai para R$ 1.192,77; economia total estimada de R$ 5.058,96 no contrato

Contract rate below the BACEN average

Input: Taxa contratual de 5% ao mês contra uma taxa média BACEN hipotética de 6% ao mês, mesma modalidade
Expected output: Razão de 0,83, diferença de -1 ponto percentual; a ferramenta não aponta indício de abusividade pelo critério da taxa média

The same review under the SAC system

Input: O mesmo contrato do exemplo anterior, recalculado pelo sistema SAC em vez do Price
Expected output: Primeira parcela recalculada R$ 1.433,33, última parcela R$ 883,33, total revisado R$ 13.900,00 (economia de R$ 5.472,20 no contrato)

Full tool FAQ

When is a bank interest rate considered abusive?

The STJ does not adopt a fixed percentage. It analyzes whether the rate notoriously diverges from the market average, causing exaggerated disadvantage to the consumer (CDC art. 51, IV).

How to obtain the BACEN average rate?

Is there a statute of limitations for revision actions?

What evidence is needed for a revision lawsuit?

Can paid-off old contracts be revised?

Does being above the BACEN average already make the rate abusive?

How does the tool recompute the revised installment?

Does the calculator prove that the contract is abusive?

Frequently asked questions