Tools workspace

All Ferrum Nexus calculators and simulators in one place. Choose a tool from the sidebar or the cards below.

Mindful credit-card spending

Simulate instalments with money invested, monthly withdrawals and cashback or points and miles.

Purchase & card

Purchase price (R$)InstalmentsFinancing rate (% monthly)First paymentInvestment start

CDB & taxation

Investment modelReferenceCDI participationCDI: —% a.a. · —Maturity (months)Daily-liquidity CDB. Partial withdrawals deduct tax on the income portion. Net proceeds are reinvested at maturity.

Card benefits

BenefitCashback (%)

Loading CDI. If unavailable, choose a custom rate.

Assumptions & rules

The purchase amount is invested in one CDB before the first payment. Returns are gross; regressive income tax and IOF before 30 days apply only to the withdrawn profit portion. The final remaining balance is liquidated too. Maturities restart the tax holding period. Rates stay constant; returns are not guaranteed.

Price instalments, first due today or next month. Cashback is deducted once; miles are a quantity, without a cash value. Annual card fees, cash-payment discounts, credit IOF and unreported charges are excluded.

Official income-tax table