金融

借り換え計算機

住宅ローン借り換えの損益分岐点と月々の節約額を計算します。

Current Loan

$
%
yrs

New Loan

%
$

Typical: 2–5% of loan amount

Monthly Savings
$—
Break-Even Point
— months
Current Payment
$—
New Payment
$—
Interest Saved (Lifetime)
$—
Total Cost Difference
$—
使い方
  1. Enter your remaining loan balance.
  2. Enter your current interest rate and remaining term.
  3. Enter the new rate you've been offered and your desired term.
  4. Add closing costs (usually 2–5% of loan; estimate if unsure).
  5. The calculator shows your monthly savings and the break-even point — how many months until your savings exceed the closing costs.

計算式

Monthly Payment = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]
Break-Even = Closing Costs ÷ Monthly Savings
P = Principal (remaining balance)
r = Monthly interest rate
n = Number of payments

Refinancing makes financial sense when the monthly savings exceed your closing costs before you plan to move. The break-even point is the key metric — if you stay in your home beyond that point, you come out ahead. Read more at CFPB's refinancing guide.