Mortgage Early-Repayment Savings Calculator
See exactly how much interest and time you save by paying extra toward your mortgage principal — no lead forms, no loan offers, just the math.
Current loan balance
Extra payments
Total transferred this month $2,096.20
Loan balance over time
Full payment schedule
How this calculator works
Enter your current loan balance, interest rate, and remaining term, then add an extra payment — recurring or one-time. The calculator runs the same month-by-month amortization schedule your lender uses, with and without the extra payment, and shows the difference in total interest and payoff time. Choose whether the extra payment should shorten your loan term (keeping your regular payment the same) or lower your monthly payment (keeping your original payoff date) — most calculators only offer the first option, but many lenders let you pick either.
Frequently asked questions
Where does the calculation come from?
This calculator uses the standard fixed-rate loan amortization formula — the same formula used across the mortgage industry and in financial-math textbooks, not something invented for this tool. It is not a substitute for the exact amortization schedule your lender provides, which may round or apply payments slightly differently.
Does "shorten the term" or "lower the payment" save more interest?
Shortening the term almost always saves more total interest for the same extra payment amount, because your balance shrinks faster and stops accruing interest sooner. Lowering the payment gives you more monthly cash flow instead — useful if your priority is flexibility rather than maximum interest savings.
Should I enter my extra payment "on top" or as the "whole transfer"?
It depends on how you think about your budget. If you already know your regular payment and want to add, say, $200 more — use "On top of the regular payment". If you're planning to send a round number like $2,000 total and want the calculator to work out how much of that actually goes to extra principal — use "The whole transfer". Both produce the same numbers if you do the subtraction yourself; this just saves you the arithmetic.
Is this financial advice?
No. This is not financial advice. Results are an estimate based on the numbers you enter, not a loan offer from any lender. Confirm any prepayment terms, fees, or restrictions with your actual mortgage servicer before making extra payments.
Part of Finance Calculators