CDB Multi-Scenario Calculator
Simulate CDB pre, post (% of CDI) and hybrid (IPCA + spread). With regressive IR. Final value and net yield.
How CDB yields work
A CDB (Certificado de Depósito Bancário) is a bank debt note: you lend money to the bank and it returns principal plus interest. Three flavors exist. Post-fixed (the most common) pays a percentage of CDI — e.g. "110% of CDI". Pre-fixed locks a fixed annual rate for the entire term. Hybrid pays IPCA + fixed %, protecting purchasing power. The gross-yield formula in business days is M = C · (1 + i)^(d/252), where i is the effective annual rate.
IR follows the regressive table: 22.5% up to 180 days, 20% 181-360, 17.5% 361-720, 15% above 720. Example: R$ 10,000 in a CDB at 110% of CDI for 1 year (CDI = 15%) yields R$ 1,650 gross; IR at 17.5% is R$ 289 → R$ 1,361 net. Liquidity varies a lot: some CDBs are D+0 (same-day withdrawal), others D+1, D+30, D+360, or only at maturity.
Brazilian context in 2026
With Selic at 15%, the daily-liquidity CDB market hovers at 100-105% of CDI; smaller or less-known banks push to 115-120% to compensate for higher credit risk. FGC covers up to R$ 250,000 per CPF per financial conglomerate, so spreading larger amounts across institutions is standard practice. Use cases: emergency reserve (daily-liquidity CDB), 1-3 year goals (pre or post-fixed), and inflation protection (IPCA+). Online brokers display the rate menu side by side — always compare net rates, not gross.
FAQ
Is a CDB at 120% of CDI a scam? Not necessarily — small banks pay more to attract deposits. As long as the issuer is FGC-protected and your total exposure to that conglomerate stays under R$ 250,000 (including interest), the risk is bounded.
Can I withdraw before maturity? Only if the CDB has explicit early liquidity. Otherwise you wait for vencimento, or the broker may offer a secondary-market sale at a discount.
What is IOF on a CDB? IOF applies only in the first 30 days, on a sliding scale (96% on day 1 down to 0% on day 30). After 30 days there is no IOF — only IR on withdrawal.
Does the bank tax me directly? No — IR is withheld at source (na fonte) by the custodian when you redeem. The net amount that hits your account is already after IR.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.