Personal finance

Four decisions, four calculators

A handful of choices weigh most on a household budget: taking out a loan, deciding where to keep savings, planning a long-term goal and changing cars. Each calculator in this section answers one of them with the full sum, not just the figure in the advert.

Before you borrow: SAC or Price?

The loan calculator shows the total you pay, how much of it is interest and how the balance falls month by month. Under SAC (sistema de amortização constante, constant amortisation) the instalment starts high and ends low; under the Price table (the French or annuity method) it stays fixed. Borrowing R$80,000.00 at 1% a month over 12 months, SAC adds up to R$5,200.00 of interest and Price to R$5,294.84. Add insurance and fees to see an approximate CET (custo efetivo total, total effective cost); the official CET is the one in the lender's offer.

Compound interest: time doing the work

Interest earns interest, so 1% a month is about 12.68% a year, not 12%. The compound interest calculator shows this with monthly contributions: R$10,000.00 up front plus R$1,000.00 a month at 1% a month reaches R$39,670.81 after 24 months, R$5,670.81 of it interest. Use it to plan a goal and see how much the time horizon matters.

Where to keep your money

To compare Brazil's common low-risk options, use the savings vs CDB vs Tesouro Selic calculator. It runs the poupança savings account, a CDI-linked bank CDB and the Tesouro Selic government bond with the same amount and term, then deducts what really comes off the return: IOF on redemptions within 30 days, regressive income tax on the CDB and Tesouro, and any custody fee. The poupança is tax-free for individuals but only pays on monthly anniversaries. Default rates come from the Central Bank and are editable.

Electric or combustion car

The sticker price is only part of the bill. The electric vs gas car cost calculator adds electricity or fuel, IPVA (the annual state vehicle tax), insurance and maintenance, subtracts estimated resale and shows cost per month, per km and how many months the price gap takes to pay back. Defaults are examples; IPVA, for one, varies by state.

Getting the most out of them

Run more than one scenario — another term, down payment or rate — and save each with the “Copy simulation link” button. Results are estimates and do not replace the lender's formal offer, your broker's statement or professional advice.