Updated October 5, 2026
In this guide
A fair comparison
Changing system, rate and term together hides the source of a difference. This comparison fixes PV = BRL 300,000, n = 360 and the same BCB rate. Only amortization method changes.
| Aspect | SAC | Price |
|---|---|---|
| Early amortization | Higher and nearly constant | Lower and rising |
| Financial payment | Declining | Level without indexation |
| Early balance | Falls faster | Falls more slowly |
Side-by-side results
BCB reference rate for fixed-rate real-estate financing: 2026-08, median of 3 institutions.
Parameters used
- Financed amount
- R$300,000.00
- Term
- 360 months
- Interest rate
- 15.1161% effective per year
- System
- SAC
- Monthly adjustment
- —
- Extra amortization
- —
Calculated results
| Scenario | SAC | Price |
|---|---|---|
| First payment | R$4,373.33 | R$3,592.64 |
| Last payment | R$844.38 | R$3,603.72 |
| Total interest | R$638,972.53 | R$993,361.48 |
| Total paid | R$938,972.53 | R$1,293,361.48 |
| Effective term | 360 months | 360 months |
| Accumulated adjustment | R$0.00 | R$0.00 |
Selected installments
| Payment no. | Payment | Interest | Amortization | Closing balance |
|---|---|---|---|---|
| 1 | R$4,373.33 | R$3,540.00 | R$833.33 | R$299,166.67 |
| 12 | R$4,265.16 | R$3,431.83 | R$833.33 | R$290,000.04 |
| 60 | R$3,793.17 | R$2,959.84 | R$833.33 | R$250,000.20 |
| 180 | R$2,613.17 | R$1,779.84 | R$833.33 | R$150,000.60 |
| 360 | R$844.38 | R$9.85 | R$834.53 | R$0.00 |
How to interpret
SAC tends to have a higher first payment and lower total interest because principal falls earlier. Price tends to start lower but holds a larger balance longer. The exact gap is derived from the rate and term.
A borrowing decision also requires the CET, index, costs and prepayment rules. This comparison isolates only the mathematics.
What may differ in a contract
- Real proposals seldom differ only by system; verify the rate, CET, index, insurance and term.
- Some Price contracts include monetary adjustment or charges that change the total payment.
Limits of this analysis
- The result does not choose a suitable system or forecast future income.
- It excludes indexation, ancillary costs, taxes and approval conditions.
Sources and review
- Central Bank of Brazil — Citizen Calculator · July 27, 2026