Savings vs CDI Comparison

Savings account vs. CDB tracking CDI

Brazilian savings (poupança) yields 0.5% per month + TR whenever Selic is above 8.5% per year, and 70% of Selic + TR otherwise. CDBs are typically quoted as a percentage of CDI, the interbank rate that hugs Selic almost perfectly. Gross CDB return is i_cdb = (% of CDI) · i_CDI; net return subtracts the regressive income tax: 22.5% under 180 days, 20% to 360 days, 17.5% to 720 days, and 15% beyond. Savings is exempt from income tax.

Scenario for 2026 with Selic at 15% per year: savings yields roughly 6.17% per year net (tax-exempt). A CDB at 100% of CDI yields about 14.9% gross, dropping to roughly 12.7% net after 2 years of holding. Even a conservative CDB at 80% of CDI clears 10% net per year — comfortably above savings. The crossover is around 50% of CDI: below that, savings wins on after-tax basis only in very short horizons.

When does savings still make sense?

Two real advantages: D+0 liquidity (instant withdrawal) and the psychological simplicity of the monthly anniversary date — withdrawing before it loses the period's yield, which trains discipline. Both savings and CDBs are protected by FGC up to R$ 250,000 per CPF per institution, so credit risk is comparable for small investors. Useful applications: basic financial education, choosing the vehicle for an emergency reserve, broker comparisons.

FAQ

What is TR? Taxa Referencial, a daily-published reference rate. Since 2018 it has been close to zero, so savings yield is effectively just the 0.5% per month floor when Selic is above 8.5%.

Why does savings underperform even at the same headline rate? Because CDBs compound interest on every business day while savings pays only once per month, on the deposit anniversary. Withdrawing one day early erases the entire month's return.

Are LCI and LCA better than CDBs? Often yes — they are tax-exempt for individuals, so a 90% CDI LCI usually beats a 100% CDI CDB net of tax. The catch is longer minimum holding periods (typically 90 days or more).