そろばん屋 · 6 号室
Loan / Mortgage Calculator
Monthly payment, total interest and amortization schedule.
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Principal Interest
Amortization schedule
| Year | Principal paid | Interest paid | Remaining balance |
|---|
Monthly payment formula
For a fixed-rate loan the monthly payment is calculated with the standard amortization formula:
M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)
where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12 ÷ 100) and n is the number of monthly payments. With a 0% rate the payment is simply P ÷ n. Each month, interest is charged on the remaining balance (balance × r) and the rest of the payment reduces the principal — which is why early payments are mostly interest.
How much do extra payments save?
Any extra amount goes straight to principal, so less interest accrues in every later month. Enter an extra monthly payment to see the shorter payoff date and lower total interest.
Does this include taxes and insurance?
No — mortgage payments often also include property tax, insurance and fees (PITI). Add those separately for a full budget.