Mortgage Payoff Calculator

See how extra payments save you years and thousands in interest

$
%
$
$
Time Saved
Enter loan details above to see savings
Time Savedvs standard payment
Interest Savedtotal over loan life
Standard Payoff
New Payoff Date
Standard Interest
New Total Interest

Standard vs. Extra Payment Comparison

📅Standard Payment
Monthly
Loan Term
Payoff Date
Total Paid
Total Interest
💰With Extra Payment
Monthly
Loan Term
Payoff Date
Total Paid
Total Interest
Your Interest SavingsAdd extra payment above to see savings

How Extra Mortgage Payments Work

When you make an extra payment on your mortgage, it goes directly to the principal — reducing your loan balance immediately. A lower balance means less interest accrues next month, so more of every future payment goes to principal too. This compounding effect accelerates payoff significantly.

Monthly interest = balance × (annual rate ÷ 12 ÷ 100)
Principal paid = monthly payment − interest
New balance = old balance − principal paid − extra payment
💡

Key insight: An extra $200/month on a $300K mortgage at 6.5% saves approximately $68,000 in interest and pays off the loan about 6 years early. The earlier in the loan you start extra payments, the more you save.

Strategies to Pay Off Your Mortgage Faster

Every strategy below reduces your principal faster — cutting interest and shortening the loan term.

  • Round up your payment — if your payment is $1,847, round up to $1,900 or $2,000. Even $53 extra per month adds up to significant savings over 30 years.
  • Make biweekly payments — paying half your monthly amount every two weeks means 26 half-payments (= 13 full payments) per year instead of 12. That one extra payment per year cuts years off the loan.
  • Apply windfalls to principal — tax refunds, bonuses, and inheritances applied directly to your mortgage principal shave years off your loan term.
  • Refinance to a shorter term — switching from a 30-year to a 15-year mortgage at a lower rate dramatically cuts total interest, though monthly payments will be higher.
  • Never skip extra payments — consistency matters most. Even one extra payment per year for 30 years cuts meaningful time off the loan.

Frequently Asked Questions

How do extra mortgage payments reduce my loan?

Extra payments go directly to the principal balance. A lower principal means less interest accrues each month — so more of future regular payments also go to principal. This acceleration shortens your loan term and reduces total interest paid.

Do I need to notify my lender about extra payments?

Yes — specify that the extra amount is for "principal only." Without this instruction, some lenders may apply extra money toward next month's payment (which still includes interest) rather than reducing principal directly.

Is there a prepayment penalty?

Some mortgages include prepayment penalty clauses, especially adjustable-rate or older fixed-rate loans. Check your loan documents or ask your lender before making large extra payments.

What is mortgage amortization?

Amortization is how loan payments are split between interest and principal over time. Early payments are mostly interest; later payments are mostly principal. Extra payments shift more toward principal immediately, accelerating the payoff.

Should I pay extra on my mortgage or invest?

Paying extra gives a guaranteed return equal to your mortgage rate. Investing may yield higher returns but involves market risk. If your mortgage rate is above 6–7%, paying down debt is often the better risk-adjusted choice. Below 5%, investing typically wins over the long term.

How much can I save with $100 extra per month?

On a $300,000 mortgage at 6.5%, an extra $100/month saves roughly $38,000 in interest and cuts 3–4 years off the loan. Enter your specific numbers above to see your exact savings.

Why trust ComputeZap?

Formulas verified against official standards
Runs entirely in your browser — no data sent anywhere
Instant results — accurate to 6 decimal places
Free forever — no signup, no ads between results