What does one extra loan payment actually change?
An extra payment reduces later interest only when it reduces the balance used for interest calculations. The first two months provide a simple way to inspect that mechanism.
Loan calculator →Separate interest from principal
In a monthly-interest model, interest for the period equals the opening balance multiplied by the monthly rate. The scheduled payment covers that interest and reduces principal with the remainder. Before assuming an overpayment accelerates the loan, check how the lender applies it. Advancing a due date and reducing the interest-bearing balance are not descriptions that should be treated as interchangeable without checking the statement.
Reconcile the first month yourself
Start with a 10,000 balance, a 1% monthly rate and a scheduled payment of 300. Interest is 100, principal reduction is 200 and the closing balance is 9,800. Add 100 that is fully applied to principal and the closing balance becomes 9,700. At the same rate, the next period’s interest is 97 rather than 98. This illustrates the immediate effect without inventing a complete contractual payoff schedule.
Check how later payments are handled
Repeated overpayments alter the balance path, but a lender may shorten the term, recalculate payments or charge a fee. The example excludes charges, arrears and rate changes. Reconcile the principal entries on actual statements. For an existing mortgage, use the payoff tool with the remaining balance and remaining term rather than the original property price.
Try the calculators
- Loan calculator
Compare terms and see what borrowing will cost.
- Mortgage payoff calculator
Compare payoff time, scheduled payments, interest and fees.
- Amortization calculator
See principal, interest and balance for every payment.