Loan calculator (SAC vs Price)
Simulate the installments of a mortgage or car loan in the SAC and Price systems.
In Price the installment is fixed throughout. Estimate without insurance and admin fees.
How the calculation works
Two amortization systems dominate Brazilian credit:
- Price: fixed installment.
PMT = V · i / (1 − (1+i)^−n) - SAC: fixed amortization (
V/n); installment starts higher and decreases, with less total interest.
Price vs SAC in the default example
R$200,000 financed, 1%/month, 360 months:
| Price | SAC | |
|---|---|---|
| First installment | R$2,057 | R$2,556 |
| Last installment | R$2,057 | R$561 |
| Total paid | R$740,602 | R$561,000 |
| Total interest | R$540,602 | R$361,000 |
With SAC, accepting a ~R$500 higher first installment saves ~R$180k in interest over the contract.
Compare the total effective cost
Interest rate alone hides mandatory insurance and fees. Always compare the full effective cost (CET), which Brazilian banks must disclose.
Examples
- R$200,000 at 1%/mo over 30 years: Price = fixed R$2,057; SAC starts at R$2,556 and ends at R$561 — with R$180k less interest.
- Shorter term, far less interest: the same R$200,000 over 240 months (Price) costs R$2,202/month but ~R$212k less interest than 360.
Frequently asked questions
SAC or Price: which pays less interest?
SAC usually pays less total interest, but the first installments are higher. Price has a fixed, more predictable installment.
Is early repayment worth it?
Almost always, if the loan rate exceeds what your investments earn. Prefer shortening the term (saves more interest) over lowering the installment.
Why is the real installment higher than the calculator?
Brazilian mortgages add mandatory insurance and admin fees, plus indexation in many contracts. Compare using the CET (total effective cost).
Which is better, SAC or Price?
If you can afford the higher first instalment, constant amortization (SAC) is almost always cheaper. On R$200k over 30 years at 1% a month it saves roughly R$179k, but demands about R$500 more upfront.
Should I shorten the term or lower the payment?
To save interest, always shorten the term. In the R$200k example, an extra R$200 a month clears the debt in 18 years 3 months instead of 30 and saves about R$248k.
What is the CET and why does it matter more than the rate?
The Total Effective Cost bundles interest, mandatory insurance (MIP and DFI) and fees. Two banks can advertise the same rate with very different CETs. Lenders must disclose it before signing.
Can I use FGTS in the mortgage?
Yes: as a down payment, to amortize the balance or to cover part of the instalments, subject to the fund rules. Since FGTS yields little, using it against expensive debt usually pays off.
What costs come on top of the mortgage?
Transfer tax, registry and appraisal fees typically add 4–5% of the property value and usually cannot be financed — plan for them alongside the down payment.
Sources and references
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Updated on July 2, 2026 · by Rafael Rossi · Methodology & sources