What is SAC Amortization Table? Simple explanation

Q: What is SAC Amortization Table?

Constant Amortization System. A loan repayment method where installments decrease over time as the principal is reduced.

What is the SAC Table?

SAC (Constant Amortization System) is a loan repayment method where the amortization amount (the part that reduces the debt) is the same for all installments. As the interest decreases as the outstanding balance falls, the installments become smaller over time.

How does it work?

Amortization: fixed (loan amount ÷ number of installments)
Interest: calculated on the outstanding balance (decreases every month)
Installment: amortization + interest (starts high, ends low)

Practical example

Financing of R$ 120,000 in 10 years (120 months) at 1% per month:

Monthly amortization: R$ 120,000 ÷ 120 = R$ 1,000
1st installment: R$ 1,000 + R$ 1,200 (interest) = R$ 2,200
60th installment: R$ 1,000 + R$ 610 = R$ 1,610
120th installment: R$ 1,000 + R$ 10 = R$ 1,010

SAC vs. Price

	SAC	Price
Installments	Decreasing	Fixed
Total interest	Lower	Higher
First installment	Higher	Lower
Ideal for	Those who can pay more at the beginning	Those who need a fixed installment

When to choose SAC

When your income allows you to pay larger installments at the beginning
When you want to save on total interest
For long-term financing (the difference is huge)
When you plan to amortize ahead of schedule