CD (CDB) calculator
Enter the amount, the CDI rate, the percentage of the CDI the CD pays and the term to see gross return, tax and net.
Free · no sign-up The values you type stay in your browser: nothing is sent or stored.
Net amount
R$10,866.25
- Gross amount
- R$11,050.00
- Income tax
- R$183.75
- Net return over the term
- 8.7%
Your result in words
Investing R$10,000.00 at 100% of a 10.5% CDI for 12 months, the gross amount reaches R$11,050.00. After R$183.75 of income tax, the net is R$10,866.25, a return of 8.66%.
Informational estimate, without fees or inflation. Check taxes and charges for your case; the real result may differ.
How it works
How a CDB earns
A CDB pays a percentage of the CDI, the interbank deposit rate. With the yearly CDI and the contracted percentage, the money compounds and, at redemption, income tax applies only to the gain.
What is left out
Use the current CDI, which follows the policy rate: the calculator does not fetch rates. Financial transaction tax (first 30 days only), custody fees and CDI changes over the term are not included.
Formula
How to calculate
i is the yearly rate (CDI times the contracted percentage), CDI the yearly CDI, p the CDI percentage, M the gross amount, P the amount invested, m the term in months, IR the income tax and a the regressive rate: 22.5% up to 180 days, 20% up to 360, 17.5% up to 720 and 15% above.
Example
With round numbers, so you can check the math:
Investing R$10,000.00 at 100% of a 10.5% CDI for 12 months, the gross amount reaches R$11,050.00. After R$183.75 of income tax, the net is R$10,866.25, a return of 8.66%.
Frequently asked questions
Where do I find the current CDI?
On the Central Bank or B3 websites. It follows the policy rate, so the field is editable.
Why does the tax drop over time?
Fixed income tax is regressive: the longer the money stays invested, the lower the rate, down to 15% after 720 days.
Does a daily-liquidity CDB pay the same?
It usually pays less. Adjust the CDI percentage to what your CDB offers.
Math checked by the JuntaTudo team · updated on Nov 12, 2026
