Updated October 2, 2026
How to calculate CET (total effective cost)
Enter what hits your account and what you pay each month. The total effective cost is shown per month and per year.
Also searched as custo efetivo total, loan APR Brazil and real interest rate calculator.
Quick answer
CET is the annual rate that adds up interest, fees, insurance and taxes on the contract. On R$10,000 repaid as 24 × R$500 it is 19.75% a year; if R$350 of costs are deducted at release, you receive R$9,650 and CET rises to about 24.20% a year.
Your result
Approximate CET
0.00%
- Net amount received
- R$0.00
- Total paid
- R$1,200,000.00
- Finance charge
- R$1,200,000.00
- Monthly effective rate
- 0.00%
How we got this number
CET is the rate that equates what you actually receive with the instalments you pay, after fees, insurance and IOF. We solve a monthly IRR by bisection and annualise it as (1+i)^12 − 1. CMN Resolution 4.881/2020 requires lenders to compute CET on calendar days and state it as an annual rate; we use months, so the second decimal can differ from the lender’s figure.
Formula and rules
Find i such that net_received = Σ instalment / (1+i)^t. Annual CET ≈ (1+i)^12 − 1.
Examples
Fees taken upfront
Face value R$10,000, R$350 in costs, 24 × R$500. You receive R$9,650 and CET is about 24.20% a year (1.82% a month), against 19.75% without the costs.
Frequently asked questions
Is this the official Central Bank CET?
No. It is an IRR of the cash flow you typed. Lenders must compute CET on calendar days and give you the calculation statement before you sign (CMN Resolution 4.881/2020, articles 7 and 8).
Must the lender disclose CET?
Yes, before you sign and with the calculation statement (CMN Resolution 4.881/2020, article 7). CET must also appear in ads that quote the interest rate (article 8).
How do I calculate the CET of a loan?
Compare what you receive on day zero with all the instalments: CET is the rate that equates the two sides. On R$10,000 repaid as 24 × R$500 it is 19.75% a year; if R$350 of costs are deducted at release, it rises to about 24.20% a year.
Related calculators
Related guides
Official sources used
Calculations run in your browser. We never ask for CPF, email or bank details, and values are not sent to our servers.
These tools provide educational estimates only. They are not a credit offer, financial advice, or an approval guarantee. Always check your payslip, contract and the current official rules.