Real Estate Financing Calculator (Price vs. SAC Amortization)
Compare decreasing installments (SAC) with fixed installments (Price), simulate prepayments and visualize the complete amortization schedule with insurance and fees.
Practical Guide: Choosing Between SAC and Price Schedules
Core financial concepts to minimize mortgage costs and build real estate wealth.
Sistema de Amortização Constante (SAC)
No sistema SAC, a amortização mensal é fixa ($A = PV / n$) e o saldo devedor diminui em ritmo constante desde o primeiro mês. Os juros incidem sobre um saldo que encolhe a cada pagamento, fazendo com que as parcelas sejam decrescentes. É a modalidade mais recomendada para quem deseja pagar o menor valor possível de juros ao longo do contrato e possui capacidade financeira para arcar com as primeiras prestações.
Tabela Price (Sistema Francês)
Na Tabela Price, a prestação básica permanece constante durante todo o prazo do financiamento. Nos primeiros anos, a maior fração da parcela é composta por juros e a amortização da dívida é reduzida. Sua principal vantagem é a previsibilidade do fluxo de caixa e o fato de a primeira parcela ser sensivelmente menor que na SAC, permitindo aprovação de crédito com uma renda familiar menor sob a regra bancária dos 30%.
Perguntas Frequentes sobre Financiamento Imobiliário
1.What is the practical difference between SAC and Price?
Under the SAC schedule (Constant Amortization System), the principal repaid each month is fixed. Because interest is charged on a shrinking balance, monthly payments decline steadily over time. Under the Price schedule (French Amortization System), total monthly payments remain constant; initially you pay mostly interest, with principal repayment increasing later. SAC always yields a lower lifetime total interest cost.
2.When is it advantageous to choose the Price schedule?
Price is beneficial when your current household income cannot qualify for the higher initial installments of SAC (which start 20% to 35% higher), or when you prefer immediate cash flow predictability to allocate funds towards renovations, reserves, or productive investments.
3.How do early principal prepayments work?
When making prepayments, you can either: (1) Reduce term, keeping payments unchanged and cutting off future years of interest; or (2) Reduce payment, lowering your monthly required payment while preserving the original payoff date.
4.What are MIP and DFI insurances and administrative fees?
These are mandatory loan charges under mortgage regulations. Life and disability insurance (MIP) pays off the debt in case of death or permanent disability of the borrowers. Physical casualty insurance (DFI) protects the collateral property against perils such as fire or structural collapse. Administrative fees cover monthly loan servicing.