One extra payment a year saves roughly 3 to 5 years of payments and $40,000 to $60,000 in interest on a typical 30-year mortgage
The exact savings depend on three things: your loan amount, your interest rate, and how early in the loan you make the extra payment. A $300,000 mortgage at 6.5% interest will save more in dollars than a $150,000 mortgage at the same rate, but the percentage of interest saved is similar. Making the extra payment in year 1 saves more than making it in year 15, because the extra principal reduces the balance that accrues interest for the remaining 29 years.
The math is straightforward: one extra payment per year equals one-twelfth of your annual payment going straight to principal instead of being split between principal and interest. Over time, that compounds. You pay off the loan faster, which means fewer months of interest charges.
Key Takeaways
- One extra payment yearly typically shortens a 30-year mortgage by 3 to 5 years and saves $40,000 to $60,000 in total interest, though the exact amount depends on your loan size and rate.
- The earlier you make extra payments, the more interest you save, because the extra principal reduces the balance that accrues interest for the remaining years.
- Making extra payments does not change your regular monthly payment amount or your loan terms—you simply pay down principal faster.
- Some lenders charge prepayment penalties, so check your loan documents before sending extra payments; most mortgages issued in the last 15 years do not.
How the savings actually work on your loan
When you make a regular monthly payment on a mortgage, part of it goes to interest and part goes to principal. Early in the loan, most of your payment is interest. On a $300,000 loan at 6.5%, your first payment might be $1,896, with $1,625 going to interest and only $271 to principal.
An extra payment of $1,896 goes entirely to principal because you are not paying interest on it—you are reducing the balance. That single payment cuts the remaining balance by $1,896 and eliminates all the interest that would have accrued on that $1,896 for the next 29 years. That is where the compounding happens.
If you make one extra payment in year 1, you save interest on that $1,896 for 29 years. If you make it in year 15, you save interest on it for 15 years. The difference in total savings can be $10,000 or more, depending on your rate.
Comparing one payment versus biweekly payments
Some people make biweekly payments (half the monthly payment every two weeks) instead of one lump-sum extra payment. Biweekly payments result in 26 half-payments per year, which equals 13 full payments instead of 12. The total interest saved is nearly identical to making one extra payment yearly, but the timing is different.
With biweekly payments, you reduce the balance gradually throughout the year. With one lump-sum payment, you reduce it all at once. The end result—shaving 3 to 5 years off the loan and saving $40,000 to $60,000—is the same. Choose whichever fits your cash flow better. If you get a bonus once a year, one lump payment is simpler. If you get paid biweekly, biweekly mortgage payments may be easier to manage.
What to check before sending extra payments
Most mortgages issued in the last 15 years allow you to pay extra principal without penalty. However, some loans—particularly those sold to investors or held by certain lenders—include a prepayment penalty that charges you a fee if you pay off the loan early or pay down principal faster than scheduled.
Check your loan documents (the note or promissory note, usually in your closing papers) for language about prepayment penalties. If you cannot find it, call your lender and ask directly: "Does my loan have a prepayment penalty?" If it does, the penalty is usually a percentage of the amount you pay early, or a flat fee, and it expires after a set number of years (often 3 to 5).
If there is no penalty, you can send extra payments whenever you have the cash. Most lenders allow you to specify that the extra amount goes to principal, not toward next month's payment. Write "apply to principal" on the check or note it in the online payment system.
The difference between $40,000 and $60,000 in savings
The range depends on your interest rate and loan amount. A higher rate means more interest accrues each month, so extra principal payments save more in dollars. A larger loan balance means more interest overall, so the savings are larger.
| Loan Amount | Interest Rate | Approximate Interest Saved (One Extra Payment Yearly) | Years Shortened |
|---|---|---|---|
| $200,000 | 5.5% | $28,000–$32,000 | 3–4 years |
| $300,000 | 6.5% | $48,000–$56,000 | 4–5 years |
| $400,000 | 7.0% | $68,000–$78,000 | 4–5 years |
These are approximations based on making one extra payment in year 1. If you make extra payments every year for 10 years and then stop, your total savings will be higher. If you make extra payments starting in year 10, your savings will be lower because there are fewer years left for the interest to compound.
When extra payments make less sense financially
Extra mortgage payments are not always the best use of money. If you have high-interest debt (credit cards, personal loans above 8%), paying that down first usually saves more money overall. If you have no emergency fund, building one should come before extra mortgage payments.
If your mortgage rate is very low (below 3%), the opportunity cost of extra payments is worth considering. Money you put toward the mortgage could potentially earn more in a stock market index fund or other investment over the long term. This is a personal decision based on your risk tolerance and financial goals, not a hard rule.
If you are planning to sell or refinance within 5 years, extra payments may not save you much because you will not keep the loan long enough for the interest savings to add up. Calculate the payoff date and compare it to your timeline.
How to actually make the extra payment
You have three main options. First, send a lump-sum payment once a year (often easiest if you get a bonus or tax refund). Second, add one-twelfth of your monthly payment to each regular payment, spreading the extra across 12 months. Third, switch to biweekly payments if your lender supports them.
When you send the payment, be explicit about where it goes. Write "apply to principal" on a check, or select that option in your lender's online portal. If you do not specify, some lenders will apply it to next month's payment instead, which delays the benefit.
Keep records of extra payments you make. Your lender should reflect them on your statement, but mistakes happen. If you ever refinance or sell, you want proof that you paid down the balance faster than the original schedule required.
Frequently Asked Questions
Does making one extra payment a year lower my monthly payment?
No. Your monthly payment stays the same. The extra payment shortens how long you owe the loan, not the size of each payment. You will eventually reach a point where the loan is paid off and you stop making payments entirely.
What if I make extra payments and then need the money back?
You cannot withdraw money you have paid toward principal. Once it is applied to the loan, it reduces your balance permanently. This is why an emergency fund matters more than extra mortgage payments if you do not have one yet.
Is it better to make one extra payment or 12 smaller extra payments?
The total interest saved is nearly identical either way. One lump payment saves slightly more because the principal reduction happens all at once. Choose based on what fits your budget: if you have cash once a year, make one payment; if you prefer spreading it out, add to each monthly payment.
Do I need to tell my lender I am making extra payments?
No, but you should specify that the extra amount goes to principal, not toward next month's payment. Most lenders allow this through their online portal or by writing it on the check. If your lender does not offer the option, call and ask how to direct extra payments to principal.
Will extra payments hurt my credit score?
No. Paying down debt faster does not harm your credit. It may slightly lower your credit score in the short term because your total available credit decreases, but the effect is minimal and temporary. Paying on time matters far more than the speed at which you pay off the loan.