Residential · Calculator
Extra Payment
See how extra principal — monthly, annual, or a one-time lump sum — shortens the loan and reduces lifetime interest.
Loan Details
Used for the payoff date.
Extra Payments
Added to every payment.
Applied at month 12, 24, 36 … Useful for tax-refund or bonus modeling.
Lifetime Interest Saved
$118,972
Loan paid off 6y 9mo early
Base vs. With Extras
Base loan
$2,128.97/mo
30y 0mo
Interest $446,428
Payoff Dec 2055
With extras
$2,328.97/mo
23y 3mo
Interest $327,457
Payoff Mar 2049
Summary
Frequently asked
About this calculator.
How do extra principal payments save money?
Every dollar of extra principal lowers the loan balance immediately, which lowers the interest charged on every future month. Even small extras compound: $200/month on a $320k 7% 30yr loan saves ~$110k in interest and pays off the loan ~7 years early.
Should I pay extra or invest the difference?
It depends on your mortgage rate vs. expected after-tax investment return. At a 7% mortgage rate, extra payments effectively earn a guaranteed 7% — hard to beat in low-risk investments. At a 3% rate, investing usually wins. Talk to a financial advisor for the full picture; this calculator just tells you what extras would do.
Will my lender apply extra payments to principal automatically?
Mostly yes, but always confirm. Some servicers default to "advance the next payment" instead of "apply to principal." Write "apply to principal" on every check or check the principal-only box in your online portal. The wrong setting wastes the entire benefit.
Is there a prepayment penalty on most mortgages?
Almost no. Conventional, FHA, VA, and USDA loans originated since the 2014 ATR/QM rules generally cannot have prepayment penalties on owner-occupied homes. Some non-QM and investment-property loans still can — read your note carefully or call us before paying extra.
Refinance vs. extra payments
Sometimes a refi beats both.
If your current rate is well above today's market, refinancing can save more than years of extra payments. We'll model both side-by-side at no cost.
Prefer to talk first? Call (707) 583-3666