Updated August 31, 2026
The scenario
One variant follows base SAC. The other adds BRL 500 from month 1, always reducing term.
How to interpret
Recurring contributions attack principal early and repeatedly. Compare total contributions, months removed and interest reduction without treating the result as advice.
BCB reference rate for fixed-rate real-estate financing: 2026-07, median of 3 institutions.
Parameters used
- Financed amount
- R$300,000.00
- Term
- 360 months
- Interest rate
- 14.9797% effective per year
- System
- SAC
- Monthly adjustment
- —
- Extra amortization
- R$500.00
Calculated results
| Scenario | Without extra amortization | With BRL 500 monthly |
|---|---|---|
| First payment | R$4,343.33 | R$4,843.33 |
| Last payment | R$844.29 | R$732.60 |
| Total interest | R$633,557.33 | R$255,689.39 |
| Total paid | R$933,557.33 | R$555,689.39 |
| Effective term | 360 months | 127 months |
| Accumulated adjustment | R$0.00 | R$0.00 |
Selected installments
| Payment no. | Payment | Interest | Amortization | Closing balance |
|---|---|---|---|---|
| 1 | R$4,843.33 | R$3,510.00 | R$1,333.33 | R$298,666.67 |
| 12 | R$4,823.92 | R$3,329.05 | R$1,494.87 | R$283,039.31 |
| 60 | R$4,600.51 | R$2,260.48 | R$2,340.03 | R$190,863.25 |
| 127 | R$732.60 | R$8.47 | R$724.13 | R$0.00 |
Limits of this analysis
- Assumes the contribution is available and processed every month until payoff.
- Does not compare contributions with investments or account for inflation.
Sources and review
- Central Bank of Brazil — Citizen Calculator · July 27, 2026