How it works
What this calculadora actually does
If you want a cdi calculadora without the sales pitch, the CDI calculadora keeps the maths honest and the steps visible, the way a spreadsheet would if you'd built it yourself.
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.
On this page you will see Taxa DI, CDI and DI treated as first-class terms — each one is linked to the calculators and references that use it, so you can follow the thread without retyping queries into a search bar.
If it helps, jump straight to the Finance hub or compare with the SELIC Rate calculadora and the Poupança vs CDB calculadora — those two calcs are the ones readers usually open right after this page.
A sample run with everything shown
The quickest way to sanity-check any formula is to try it on figures you recognise. Try these:
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.
- Misreading the unit in the label — 'per year', 'per month' and 'per day' versions of the same figure differ by 12× or 365×.
- Taking a ratio and multiplying it by the wrong side of the inputs — always write the ratio as A/B with labels before running.
- Trusting a screenshot of someone else’s calculation — rerun it yourself with the same inputs, numbers drift.
- Assuming percentages add up. 10% off then 10% more is not the original price — it is 99% of it.
- Not refreshing the page when thresholds are date-sensitive. If the page was cached yesterday, bank rates may already be yesterday’s.
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.