Calculadora de Empréstimo Pessoal
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
PMT = P·r·(1+r)ⁿ / ((1+r)ⁿ − 1)
About this calculator
The Personal Loan Calculator simulates the installment amount, total interest, and total cost of a loan. You enter the desired amount, the monthly interest rate, and the number of installments. The tool calculates the fixed installment amount using the Price system, the most common for personal loans. The result includes the total paid and the accumulated interest over the period.
The calculation uses the formula PMT = P * r * (1+r)^n / ((1+r)^n - 1), where P is the principal amount, r is the monthly interest rate (in decimal), and n is the number of installments. This formula determines the constant installment that amortizes the principal and covers interest. Note that early installments consist mostly of interest, with principal amortization increasing over time.
Use this calculator before taking out a loan to compare offers from different financial institutions. For example, simulating a $10,000 loan over 12 months at a 2% monthly rate shows the total cost quickly. This helps decide if installments fit your budget and avoid surprises with high interest.
Caution: the interest rate must be the effective monthly rate, not annual. Check if the contract includes insurance or fees that may increase the total effective cost. Remember that late payments incur penalties and additional interest. Simulate different terms: smaller installments may mean higher total interest due to longer duration.
Frequently asked questions
How do I calculate my loan installment amount?
Enter the loan amount, monthly interest rate, and number of installments. The calculator uses the Price formula to determine the fixed installment value.
What is the difference between monthly and annual interest rate?
The monthly rate is applied each month. The annual rate is higher due to compounding. Always use the monthly rate for installment simulations.
What is the Total Effective Cost (CET)?
It is the total cost including interest, fees, and insurance. This calculator shows only interest; CET may be higher.
Can I use this calculator for vehicle financing?
Yes, if the amortization system is Price (fixed installments). For SAC or other systems, use specific calculators.
How are late payment interest calculated?
Late payments incur a fine (usually 2% of the installment amount) and late interest (0.33% per month). This calculator does not include these charges.