Technology for access to justice
Interest Review Calculator
In two stages: the quick test tells whether a loan's interest exceeds the Central Bank average; the full calculator redoes balance and instalment for the review lawsuit.
Visit the official siteThe problem
Few borrowers know whether their interest is abusive. The market average rate sits in the Central Bank’s time-series system, whose interface is impenetrable to laypeople, and the maths of a loan-review lawsuit, with balance and instalment redone, is laborious.
What was built
A calculator in two stages.
The first is a preliminary test, open to the public: given the month of the loan, its type and the contract rate, it fetches the Central Bank average and shows whether the contract rate exceeds it by 20% or 50%, following the case law of the Rio Grande do Sul Court of Justice.
The second, for whoever drafts the lawsuit, is the full review calculator. It redoes the outstanding balance and the instalment under three criteria (the contract rate, the Central Bank average and the real rate built into the instalment) and produces a report with the undisputed amounts and the value of the claim.
Average rates come from the Central Bank’s open-data API and are refreshed every 12 hours. Whatever is typed is processed in the browser: nothing is sent to or stored on the server.