只付利息抵押贷款计算器 — 公式

Interest-Only Mortgages

An interest-only mortgage allows you to pay only the interest for an initial period (typically 5-10 years), after which the loan converts to fully amortizing payments.

How Payments Work

Interest-Only Period: Monthly Payment = Loan Balance x (Annual Rate / 12)

Amortizing Period: Standard P&I payment calculated on the full balance over remaining years

Advantages

  • Lower initial payments for improved cash flow
  • Useful for investors who plan to sell before amortization begins
  • Can invest the difference between IO and fully amortizing payments

    • Risks

  • No equity built during IO period (except through appreciation)
  • Payment shock when amortization begins
  • Higher total interest paid over the loan life

    • 计算示例

    A $500,000 loan at 7% interest, 10-year IO period, 30-year total term.

    1. Monthly rate: 7% / 12 = 0.5833%
    2. IO payment: $500,000 x 0.005833 = $2,916.67/month
    3. IO period interest: $2,916.67 x 120 = $350,000
    4. Amortizing period: 20 years = 240 months
    5. Amortizing payment: $500,000 over 240 months at 7% = $3,876.83/month
    6. Payment shock: $3,876.83 - $2,916.67 = $960.16 increase
    7. Amortizing period interest: $3,876.83 x 240 - $500,000 = $430,439
    8. Total interest: $350,000 + $430,439 = $780,439