Calculadora PRICE
- 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 PRICE Calculator computes the fixed installment amount for a loan using the PRICE system, also known as the French amortization system. In this system, monthly payments are constant, but the split between interest and principal changes over time: early payments consist mostly of interest, while principal repayment increases gradually. The formula used is PMT = P × r × (1 + r)^n / ((1 + r)^n − 1), where P is the loan amount, r is the monthly interest rate, and n is the number of installments.
How it works: enter the loan amount, monthly interest rate, and term in months. The calculator returns the fixed installment value and details the monthly evolution with outstanding balance, interest, principal repayment, and installment. This allows you to see how interest decreases and principal increases each month while the payment stays the same. It is useful for comparing with other systems like SAC or SACRE and understanding the total cost of the loan over time.
When to use? Mainly for real estate financing in Brazil, where the PRICE system is common for residential properties. It also applies to consortia, personal loans, or any credit operation with fixed installments. Ideal for those who want predictable monthly payments, even if the total cost is higher than in the SAC system. The calculator helps simulate different interest rates and terms, aiding decision-making before contracting a loan.
Important precautions: ensure the interest rate is monthly and effective, not annual. The calculator does not include insurance, administrative fees, or the Total Effective Cost (CET). Remember that in PRICE, the outstanding balance decreases more slowly initially, generating more total interest. Always compare with SAC if your goal is faster amortization. Use the tool as support, but consult a specialist for financial decisions.
Frequently asked questions
What is the difference between PRICE and SAC?
In PRICE, installments are fixed, with decreasing interest and increasing amortization. In SAC, installments decrease over time, with constant amortization. PRICE has lower initial payments but higher total interest.
Can I use this calculator for car financing?
Yes, as long as the financing uses the PRICE system (fixed installments). Just enter the loan amount, monthly rate, and term in months.
Should the interest rate be monthly or annual?
The rate must be monthly. If you have an annual rate, divide by 12 for a simple approximation or use compound interest equivalence.
What is CET and why is it not included?
CET is the Total Effective Cost, including interest, fees, and insurance. This calculator considers only interest. For the real cost, check the contract or use a CET calculator.
Why does amortization increase over time?
Because the installment is fixed and interest decreases (as the outstanding balance drops), the difference goes to amortization. This accelerates debt repayment in later months.