Calculator
Every payment, month by month
Where does each payment actually go?
A level payment hides a moving split. This lays the whole loan out — every payment, its interest, its principal and the balance left — and lets you read it a month at a time or a year at a time.
The loan
Set to zero to read the loan on its own.
Payment 1 splits— to interest,— to principal.
Principal overtakes interest at—.
Half the balance is gone after—.
The schedule
What this page assumes, and where it comes from
Questions this raises
Why does so little of the early payment touch the principal?
Because interest is charged on what you still owe, and at the start you owe nearly all of it. The payment is level, so the interest slice starts large and shrinks by a few dollars each month while the principal slice grows to match. The crossover — the first payment where more goes to principal than to interest — is printed above.
Is the year view just the month view added up?
Yes, exactly. Each year row is the sum of its twelve payments, and the balance shown is the balance at the end of that year. Switch between them and the totals agree to the cent; there is a test asserting it.
Can I see what an overpayment does to this?
The extra payment calculator runs the same engine with an overpayment applied, and shows both schedules side by side.