Calculadora de IOF
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
IOF = P × (0,0082% × dias + 0,38%)
About this calculator
The IOF Calculator for credit operations helps determine the amount of the Tax on Financial Operations applicable to loans, financing, and other credit modalities. The calculation considers the daily rate of 0.0082% on the principal amount, multiplied by the number of days of the operation, plus the fixed additional rate of 0.38%. The result is the total IOF due, which is deducted from the amount released to the borrower.
It works simply: enter the total credit amount (in reais) and the number of days of the operation. The calculator applies the formula IOF = P × (0.0082% × days + 0.38%), where P is the principal. For example, for a loan of R$ 10,000 for 30 days, the IOF will be R$ 10,000 × (0.000082 × 30 + 0.0038) = R$ 10,000 × (0.00246 + 0.0038) = R$ 10,000 × 0.00626 = R$ 62.60.
Use this tool to simulate the real cost of credit before contracting it. It is useful for comparing proposals from banks and financial institutions, understanding the impact of the term on the tax amount, and planning your budget. Remember that IOF applies to each credit operation, including overdraft and revolving credit card, with specific rules for each case.
Cautions: the daily rate may be changed by the government, so check the current rate. For operations with a term of less than one day, one day is considered. The additional 0.38% is fixed for individuals; legal entities may have different rates. This calculator does not include other charges such as interest and bank fees.
Frequently asked questions
What is IOF and when is it charged?
IOF is the Tax on Financial Operations, charged on credit, exchange, insurance, and securities transactions. For credit, it applies to the amount released, with a daily rate and an additional fixed rate.
How to calculate IOF for a 60-day loan?
Use the formula: IOF = loan amount × (0.0082% × 60 + 0.38%). Example: R$ 5,000 × (0.000082 × 60 + 0.0038) = R$ 5,000 × 0.00872 = R$ 43.60.
Is IOF deducted upfront or paid later?
It is usually deducted at the time of credit release, reducing the amount received. In some cases, it may be financed along with the outstanding balance.
Does the IOF rate change frequently?
Yes, the government can change rates by decree. Check the current rate on the Brazilian Federal Revenue website or use updated calculators.
Can this calculator be used for credit card IOF?
Yes, for revolving credit card the rate is the same (0.0082% per day + 0.38% fixed). For installment purchases, IOF applies to the total financed amount.