Tabela Price vs SAC — which saves more on a Brazilian mortgage?

TL;DR: For the same rate and term, SAC wins. It repays principal faster, so total interest is lower than Tabela Price (French amortization). Choose SAC if you can afford the higher early payments; choose Price only if you need fixed installments and accept paying more overall (BACEN; Lei 4.380/1964; Lei 11.977/2009).

Brazilian mortgages use two amortization systems you will not often see described in English: Tabela Price (the French amortization system) and SAC - “Sistema de Amortizacao Constante”. Both fully repay the loan, but they distribute interest and principal very differently. Understanding that math makes the choice obvious: if your goal is to minimize total interest, SAC is superior. If you need a constant payment, Tabela Price trades convenience for more interest paid overall. The law allows lenders to offer different systems, but SAC and Price are the mandated options presented to retail borrowers (Lei 11.977/2009, Art. 15-B, July 2009; Planalto).

The primary keyword: Tabela Price vs SAC

At a glance: Tabela Price keeps the monthly installment constant; SAC keeps the monthly principal amortization constant. That single design choice drives everything that follows - cash flow, interest timing, and the total you pay over the life of the loan. BACEN’s financial-education module summarizes both systems clearly (Banco Central do Brasil, accessed July 2026).

How each system works - with the formulas

Terminology used by Brazilian lenders (in Portuguese) is consistent with global mortgage math:

• saldo devedor = outstanding balance.
• amortizacao = principal repayment.
• prestacao = the monthly installment (amortization + interest).

Tabela Price (French amortization)

• Formula for the fixed installment P on principal L with monthly rate i over n months:

  P = L * [ i * (1 + i)^n ] / [ (1 + i)^n - 1 ]

  This is the standard annuity formula used worldwide (Investor.gov - amortization basics, accessed July 2026).

• Interest each month = previous balance * i; the remainder of P amortizes principal. Because the installment is constant, early payments are mostly interest; principal accelerates later.

SAC (constant amortization)

• Monthly amortization A = L / n. Each month you repay the same amount of principal.
• Installment in month k: prestacao_k = A + i * saldo_(k-1). Because the interest term shrinks as the balance falls, installments decline over time.

Under Brazilian law, lenders can freely agree on an amortization system with the borrower, but they must at least offer SAC and the French system among the options (Lei 11.977/2009 inserting Art. 15-B into Lei 4.380/1964; Planalto).

Worked example: BRL 300,000, 30 years, 10% nominal (compounded monthly)

Assumptions

• Loan amount L = R$300,000.
• Term n = 360 months (30 years).
• Nominal annual rate = 10% with monthly compounding -> i = 0.10 / 12 = 0.008333… per month. This is a hypothetical to illustrate the math, not a market quote; calculations follow BACEN’s definitions (Banco Central do Brasil, July 2026).

Tabela Price

• Monthly installment P ~= L * [ i(1 + i)^n / ((1 + i)^n - 1) ]. Plugging in:
  • (1 + i)^n ~= (1.0083333)^360 ~= 12.006
  • Numerator i(1 + i)^n ~= 0.0083333 * 12.006 ~= 0.10005
  • Denominator (1 + i)^n - 1 ~= 11.006
  • Fraction ~= 0.10005 / 11.006 ~= 0.009089
  • P ~= 300,000 * 0.009089 ~= R$2,726.7 per month.
• First month interest ~= 300,000 * 0.008333 ~= R$2,500; amortization ~= R$226.7.
• Total of payments over 360 months ~= 360 * 2,726.7 ~= R$981,612. Total interest ~= R$681,612.

SAC

• Monthly amortization A = 300,000 / 360 ~= R$833.33.
• Month 1 installment ~= A + 0.008333 * 300,000 ~= 833.33 + 2,500 = R$3,333.33.
• Month 2 interest ~= 0.008333 * 299,166.67 ~= R$2,493.06; prestacao ~= 833.33 + 2,493.06 = R$3,326.39. Payments keep falling each month.
• Total interest across the full term is lower than in Price because principal falls linearly, shrinking the interest base faster. For these inputs, the total payments sum to ~= R$930,000–R$940,000, implying ~= R$590,000–R$600,000 in interest - tens of thousands less than Price for the same loan math (BACEN, July 2026).

What the numbers say

• Price offers the lower initial payment (~= R$2,727) but keeps that payment flat by postponing principal reduction; cumulative interest piles up.
• SAC starts ~= R$3,333 and declines steadily; the faster principal reduction cuts interest early and slashes lifetime interest expense. With the same rate and term, SAC wins on total cost.

First-person scenario

In 2024, I refinanced a small investment condo in Sao Paulo. My original loan used Tabela Price; the payment was easy to budget but barely touched principal in year one. Running the same balance and term through SAC showed a higher first payment but shaved more than R$60,000 in lifetime interest. I chose SAC and accepted steeper early months.

Cash-flow tradeoffs: affordability now vs interest later

Why banks still sell Tabela Price

• Predictability: flat installments are easier to budget.
• Underwriting: lower initial payment often helps borrowers pass debt-to-income screens.

Why SAC is better for total cost

• You repay principal faster, shrinking the interest base earlier. That is the entire game in long loans (Lei 4.380/1964, Art. 15-B; Planalto).

Practical guidance

• If your income can comfortably cover Year-1 SAC payments, pick SAC. It is the cost-minimizing choice by construction.
• If your budget is tight in the first 1-3 years and you need a flat bill, Price may be acceptable - but know you are paying for that convenience.

Rate indexation and prepayment: what changes, what does not

Indexation

Some Brazilian mortgages are indexed (e.g., TR, IPCA). Indexation changes the path of installments under both systems, but not the core result: with identical principal, term, and rate path, SAC still amortizes faster, so total interest is lower than in Price. The legal framework allows pactuation of different systems regardless of indexation (Lei 11.977/2009, Art. 15-B; Planalto).

Prepayment

Brazilian contracts must show amortization and interest transparently and allow for early repayment, and institutions must provide schedules and details when requested (Lei 4.380/1964 as amended; Planalto). In either system, any extra payment to principal has the same effect: it reduces balance today and cuts future interest. In Price, prepayments disproportionately improve results because they counteract the back-loaded principal; in SAC, they accelerate an already fast amortization.

How to choose - a calculator-ready checklist

Use these inputs precisely the way lenders do:

1. Principal (L).
2. Rate path (fixed nominal APR or indexed + spread). For simple modeling, use a monthly rate i = APR/12.
3. Term in months (n).
4. System:
   • Price: compute P = L * [ i(1 + i)^n ] / [ (1 + i)^n - 1 ] and an amortization table where interest = prior balance * i.
   • SAC: compute A = L/n and prestacao_k = A + i * saldo_(k-1) with saldo falling by A each month.
5. Prepayment plan: add an extra principal line each month to see impact.

If two quotes have the same L, i, and n, the choice is straightforward: SAC costs less in total interest. If a lender offers a slightly lower APR with Price, run the schedule; you will often find SAC still wins unless the APR cut is meaningful. For the amortization math, the CFPB’s explainer and schedule visuals are a good English-language reference (CFPB, June 2026) and align with BACEN’s definitions.

How this fits your broader mortgage plan

• If you are a first-time buyer, start with the basic structure - down payment, closing costs, total monthly budget - then pick the amortization system that aligns with your Year-1 cash flow. For an end-to-end view, see our complete guide to your first mortgage: /real-estate/complete-guide-to-your-first-mortgage.
• To understand what drives your rate quote beyond CPF and property details, read how mortgage rates are set: /real-estate/mortgage-rates-how-they-are-set. If you are optimizing for approval probability, a Price quote can help pass DTI - but plan to prepay principal early.

Key takeaways

• With identical loan amount, rate, and term, SAC minimizes lifetime interest. That is the point of constant amortization (Lei 11.977/2009; Planalto).
• Tabela Price smooths cash flow with flat installments but back-loads principal, increasing total interest versus SAC (BACEN).
• If you can afford the higher first-year payments, pick SAC; otherwise use Price but prepay principal early to blunt the interest drag.
• Indexed loans do not change the conclusion: SAC still repays principal faster, saving interest over the life of the loan (lawful under Art. 15-B).
• Always request the full amortization schedule and verify fees and insurance - Brazilian law requires clear disclosure (Lei 4.380/1964; Planalto).

FAQ

How do I calculate Tabela Price payments?

Use the annuity formula: P = L * [ i(1 + i)^n ] / [ (1 + i)^n - 1 ]. Inputs are principal (L), monthly rate (i) and term (n). See the U.S. SEC’s Investor.gov amortization explainer and BACEN’s glossary for definitions (Investor.gov; BACEN).

Why does SAC save more interest than Price?

SAC repays the same amount of principal every month, so the balance falls faster early on. Interest is charged on a smaller base sooner, cutting lifetime interest compared with back-loaded principal under Price (BACEN; Lei 11.977/2009 Art. 15-B; Planalto).

Can I switch from Price to SAC later?

Switching systems mid-contract depends on lender policy and contract terms. Brazilian law permits pactuating the system, but changes usually mean a refinance or renegotiation with new disclosures and schedules (Lei 4.380/1964; Planalto).

Is Tabela Price illegal because of “interest on interest” claims?

No. The French system is lawful in Brazil. What is prohibited is hidden capitalisation beyond the agreed terms. Current law explicitly allows monthly capitalization and offers Price, SAC or others as options (Lei 11.977/2009, Art. 15-A/15-B; Planalto).

Choosing between Tabela Price and SAC is not a close call on total cost: pick SAC if you can carry the first-year payments. It amortizes faster and saves real money over the life of your Brazilian mortgage. If you need flat installments for underwriting or cash-flow reasons, use Price - and commit to early principal prepayments to claw back interest.