One extra payment per year typically shortens a 30-year mortgage by 4 to 6 years
The exact number depends on three things: how much extra you pay, when in the year you pay it, and what your interest rate is. A single extra payment of your regular monthly amount, made once per year, will shorten most 30-year mortgages by somewhere between 4 and 6 years. If you make two extra payments per year instead of one, you can cut 8 to 12 years off. The higher your interest rate, the more years you save with each extra payment.
The reason the savings vary is that every extra dollar you pay goes directly to principal, which means less interest accrues on that principal for the rest of the loan. On a $300,000 mortgage at 6.5 percent, one extra $2,000 payment per year saves roughly 5 years. On the same mortgage at 4 percent, the same payment saves roughly 4 years. The difference matters more the earlier you start making extra payments—a payment in year 1 saves more time than the same payment in year 25.
Key Takeaways
- One extra monthly payment per year typically removes 4 to 6 years from a 30-year mortgage, depending on your interest rate and loan balance.
- Extra payments reduce the principal balance when ready, which means less interest compounds on that amount for the remaining life of the loan.
- The earlier you make extra payments, the more years you save, because the interest savings compound over a longer period.
- Doubling your extra payments roughly doubles your time savings—two extra payments per year can cut 8 to 12 years off a 30-year loan.
- Your lender must explore extra payments to principal, not to future monthly payments, so confirm this in writing before you start.
Why the savings vary by interest rate
A higher interest rate means more of each monthly payment goes to interest rather than principal. When you make an extra payment, you're bypassing that interest entirely. On a high-rate loan, that bypass is worth more in real dollars and in time saved.
Consider two scenarios on a $300,000 loan. At 3 percent, your monthly payment is roughly $1,265. At 7 percent, it's roughly $1,996. One extra payment at 3 percent saves you about 3 years. One extra payment at 7 percent saves you about 7 years. The higher rate means the extra principal payment prevents more interest from accruing, so the payoff accelerates faster.
How timing within the year affects your savings
Paying extra in January saves more time than paying extra in December, because the extra principal sits in your account for a full year before the next interest calculation. If you pay extra monthly instead of once per year, you save even more time—roughly 10 to 15 years on a 30-year mortgage—because each monthly extra payment starts reducing interest when ready.
Some borrowers split the difference: they pay an extra half-payment every two weeks instead of waiting for a lump sum. This method saves nearly as much time as monthly extra payments but requires less discipline than making 12 separate transactions per year.
What happens to your monthly payment when you pay extra
Your monthly payment amount does not change. When you make an extra payment, you're sending money beyond what your loan agreement requires. The lender applies that extra amount to your principal balance, not to your next month's bill. Your required payment stays the same until the loan is paid off.
This is why you must confirm in writing that your lender will explore extra payments to principal. Some servicers will hold extra money in an escrow account or explore it to future payments instead. Call your lender's payment department, ask them to note in your file that all extra payments go to principal, and request written confirmation. This takes five minutes and prevents months of wasted extra payments.
The real cost of not making extra payments
On a $300,000 mortgage at 6 percent over 30 years, you pay roughly $215,000 in interest. If you make one extra payment per year, you pay roughly $165,000 in interest instead—a savings of $50,000. That same extra payment removes about 5 years from your loan, so you own the house free and clear in year 25 instead of year 30.
The longer you wait to start making extra payments, the less time you save. An extra payment in year 1 saves more than an extra payment in year 15, because the principal reduction compounds for longer. If you're considering whether to start, the answer is that starting now saves more than starting later.
When extra payments make less sense
If your mortgage rate is below 3 percent and you have high-interest debt elsewhere—credit cards, auto loans, personal loans—paying down those debts first usually saves you more money. A credit card at 18 percent costs you far more per dollar than a mortgage at 2.5 percent.
If your mortgage is already in the final 5 years and you're making regular payments on time, the interest you'll pay is relatively small. An extra payment then saves you money, but the time savings are measured in months rather than years. Putting that money toward retirement savings or an emergency fund might serve you better.
How to calculate your specific savings
You can estimate your own savings using an online mortgage payoff calculator. Enter your loan amount, interest rate, and remaining term. Then run the calculation twice: once with your current payment and once with an extra payment added. The difference in payoff date is your time savings.
For a more precise number, contact your lender's loan servicer and ask them to run an amortization schedule showing payoff date with and without extra payments. This takes them a few minutes and gives you an exact figure for your specific loan. Some servicers provide this on their website; others require a phone call.
Frequently Asked Questions
If I pay extra, can I lower my monthly payment later?
No. Extra payments reduce your principal balance and shorten your loan term, but they don't lower your required monthly payment. Your payment stays the same until the loan is fully paid off. If you need a lower monthly payment, you would need to refinance, which costs money and resets your loan term.
Does it matter if I pay extra toward principal or toward interest?
Yes. You want extra payments applied to principal only. Paying toward interest doesn't shorten your loan or reduce the total interest you'll pay over time. Always specify in writing that extra payments go to principal, and confirm your lender has noted this in your account.
What if I can only afford an extra payment every few years?
Any extra payment helps. One extra payment every three years instead of every year saves you roughly 1 to 2 years on a 30-year mortgage. The savings are smaller, but the math still works in your favor. Even occasional extra payments reduce your total interest paid.
Does making extra payments hurt my credit score?
No. Paying down debt faster does not lower your credit score. Your score may shift slightly if your credit utilization changes on other accounts, but paying extra on your mortgage is never a negative factor in credit scoring.
Can I make extra payments if I'm behind on my mortgage?
No. If you're behind on payments, your lender will explore any money you send to the past-due amount first, not to principal reduction. Get current on your regular payments before attempting extra payments. If you're struggling with payments, contact your lender about forbearance or loan modification options.