Mortgage Payoff Calculator · Practical guide
One Extra Mortgage Payment a Year
Thirteen payments a year instead of twelve quietly cuts years off a 30-year mortgage.
At a glance
The Short Answer
Making one extra mortgage payment each year on a $280,000 loan at 6.5% pays the loan off in 24 years 4 months instead of 30 and saves $78,386 in interest. A single additional $1,769.79 payment annually removes nearly 6 years from the schedule.
Interactive tool
Mortgage Payoff Calculator
Enter your own values, then compare the result with the examples below.
Results
| Scenario | Payoff Time | Total Interest | Total Paid |
|---|
Why One Payment Does So Much
Your required payment is mostly interest in the early years — the first $1,769.79 payment contains $1,516.67 of interest. An extra payment is 100% principal, so it permanently shrinks the balance that every future interest charge is calculated on. Repeat that once a year and the effect compounds.
Two Ways to Do It
- Lump sum: send one extra payment of $1,769.79 whenever a bonus or tax refund arrives, marked "apply to principal."
- Spread it out: divide the payment by 12 ($147.48) and add that to every monthly payment — nearly the same result with no big one-time outlay.
How It Compares to Other Strategies
| Strategy ($280K, 6.5%, 30 yr) | Payoff Time | Interest Saved |
|---|---|---|
| No extra payments | 30 years | — |
| One extra payment per year | 24 yrs 4 mo | $78,386 |
| Biweekly half-payments | 24 yrs 2 mo | $81,439 |
| $200 extra every month | 22 yrs 9 mo | $101,283 |
Before You Start
Confirm your loan has no prepayment penalty — FHA, VA, USDA, and qualified conforming loans generally cannot charge one — and tell your servicer in writing that extra funds go to principal, not toward next month's payment.
Frequently Asked Questions
Is one extra payment a year the same as biweekly payments?
Nearly. Biweekly half-payments produce 13 full payments a year and land slightly earlier in each month, saving $81,439 versus $78,386 on a $280K loan at 6.5%.
Does an extra payment lower my required monthly payment?
No. Extra payments shorten the loan and cut total interest, but the required payment stays the same unless you recast or refinance.
When in the year should I make the extra payment?
As early as possible. Interest accrues on the balance monthly, so a January extra payment saves slightly more than a December one.
What if I can only afford a small extra amount?
Even $100 a month helps meaningfully: on a $320,000 loan at 6.5%, it pays the loan off almost 4 years early and saves about $61,698 in interest.