How it works
What this calculadora actually does
CDI calculadora is built to give you a clean, explainable answer without the usual wall of ads — type the numbers, read the result, keep moving.
Small rate differences stack up over years — always run the maths before signing. Pull last month’s statement open on another tab — then run the sums and the rest of this page explains what the answer means.
Brazilian CDI-indexed investments — apply percentage-of-CDI (e.g. 110% CDI) returns and net-of-IR tax.
Following the method end to end
Here's what happens when you plug real numbers in.
Brazilian CDI-indexed investments — apply percentage-of-CDI (e.g. 110% CDI) returns and net-of-IR tax.
Moments this tool earns its keep
CDI calculadora is aimed at people arriving with questions like these:
- "Cdi hoje"
- "110% do CDI"
- "Cdi diario"
- "What is cdi"
- "How to calculate cdi"
- "Cdi formula"
Where the number stops being useful
Every tool has an edge where it stops being the right answer. CDI calculadora is no exception:
- For legally binding tax or medical decisions — cross-check with HMRC, NHS or a qualified professional.
- For very large or very small extremes the rounding error outgrows the useful precision.
- When the underlying rate or threshold has changed since the page was last reviewed — always verify with the primary source.
- When the input you have is already a derived figure (net of something) — feeding it in as "gross" will double-subtract.
Mistakes we see over and over
Every time you run the sums for a new scenario, one of these creeps in — it's worth knowing them ahead of time.
- Assuming the UK and US versions of the same unit are interchangeable — they're not.
- Typing a comma where the tool expects a dot (or vice versa).
- Rounding early — particularly painful in percentages and compound growth.
- Ignoring the time window: a 'per year' answer makes no sense with a monthly input.
- Treating the answer as private: screenshots are fine, but the URL always reruns cleanly.
The sources behind the numbers
Where the maths needs an external authority, we cross-check against:
- B3
- Banco Central do Brasil
Works well alongside
If this question keeps coming up for you, the same cluster of tools usually comes next:
- SELIC Rate calculadora — Brazilian SELIC-linked returns — apply the daily and annualised SELIC to any amount and period.
- Poupança vs CDB calculadora — Compare Brazilian poupança savings (tax-free but lower rate) against CDB (subject to IR) on the same maturity and amount.
- Fixed-Term Deposit calculadora — Project the maturity value of a UK fixed-rate bond or a Brazilian CDB/LCI, with gross and net (after tax) returns side by side.
How we keep this accurate
Our calculadoras run on pure, unit-tested functions — the same logic lives in the browser and in the CI test suite. When tax rates, thresholds or official figures move, the update lands within 24 hours of the announcement. You can read the editorial policy and corrections policy.
Found an out-of-date number on CDI calculadora or anywhere else in the Finance toolkit? Send it to the editorial desk and we'll patch it. Or browse the full calculadora directory for the next tool you need.