Start with what you can afford without breaking other goals
The right extra payment is the amount you can send every single month without cutting into emergency savings, retirement contributions, or other debt payoff. There is no universal "correct" number—it depends on your income, your other debts, and what else you need that money for.
A common starting point is an extra $50 to $200 per month, but that works only if it does not force you to skip a credit card payment, delay a car repair, or raid your emergency fund. If you are living paycheck to paycheck, an extra $20 per month is better than nothing and still saves you years of interest. If you have stable income, no high-interest debt, and three to six months of expenses in savings, you can afford to be more aggressive.
The math is straightforward: every dollar you send toward principal reduces the total interest you will pay over the life of the loan. But only if you can sustain it. A payment you make once and then stop does almost nothing. A payment you make for five years straight reshapes your loan.
Key Takeaways
- An extra payment is only worth making if you can afford it without cutting emergency savings or delaying other debt payoff.
- Sending $50 to $200 extra per month is common, but the right amount for you depends on your income and other financial obligations.
- Specify in writing that extra payments go toward principal, not into a future payment buffer, or your lender may hold the money instead of reducing what you owe.
- Paying extra twice a year (like a lump sum from a bonus) often works better than trying to stretch a small amount across twelve months.
- If you carry credit card debt or a car loan at a higher interest rate than your mortgage, paying down those first usually saves more money overall.
How to tell your lender where the extra money goes
This step matters more than most people realize. If you simply send extra money without instructions, many lenders will hold it in an escrow account or apply it to your next scheduled payment instead of reducing your principal balance. You end up paying the same total interest, just with a smaller monthly bill later.
When you make an extra payment, include a written note or call your lender's payment line and state clearly: "Apply this payment to principal only." Some lenders have an online portal where you can designate extra payments before sending them. Others require a phone call or a letter. Check your loan documents or call the customer service number on your statement to learn your lender's process.
Keep a record of every extra payment you make—the date, the amount, and the confirmation that it went to principal. If your lender later claims you did not make a payment or applies it incorrectly, you will have proof.
Lump sums often work better than small monthly additions
If you receive a bonus, tax refund, inheritance, or other windfall, a single large payment toward principal can save more interest than spreading that money across twelve months. A $1,200 tax refund sent as one payment reduces your balance immediately and starts earning interest savings right away. The same $100 per month takes twelve months to reach the same balance reduction.
Lump-sum payments also avoid the temptation to skip a month or reduce the amount when money is tight. You make one decision, send one check, and move on. Many people find this easier to stick with than a recurring monthly commitment.
If you receive regular bonuses or seasonal income, consider setting aside a portion for an annual or semi-annual principal payment rather than trying to add it to your monthly budget.
When to prioritize other debt first
If you carry a credit card balance at 18 to 24 percent interest, or a car loan at 6 to 8 percent, paying down those debts first usually saves more money than extra mortgage payments. Your mortgage interest rate is typically 3 to 7 percent. The math is simple: a dollar sent to a 20 percent credit card saves you 20 cents per year in interest, while a dollar sent to a 5 percent mortgage saves you 5 cents.
The exception is if your credit card is nearly paid off and your mortgage rate is unusually high. But in most cases, clear the high-interest debt first, then redirect that payment amount toward your mortgage principal.
This also applies to student loans at 6 percent or higher. Pay those down to a manageable level before aggressively paying extra on a 4 percent mortgage.
How much time and interest you actually save
The savings depend on three things: how much extra you send, how often you send it, and how many years remain on your loan. A $100 extra payment per month on a 30-year mortgage at 5 percent will shorten the loan by roughly three to four years and save approximately $40,000 in interest. A $200 extra payment per month on the same loan saves roughly $80,000 and shortens it by five to six years.
These numbers vary based on your exact rate, remaining balance, and loan term. You can calculate your own savings using a mortgage payoff calculator—enter your loan details, add the extra payment amount, and it will show you the new payoff date and total interest saved. Most lenders provide these tools on their websites.
The key insight: the earlier in the loan you make extra payments, the more interest you save. An extra $100 in year one saves more than an extra $100 in year twenty, because it reduces the balance that accrues interest for the next nineteen years.
Biweekly payments as an alternative to extra monthly payments
Some people switch to biweekly payments instead of monthly payments. Because there are 26 biweekly periods in a year but only 12 months, you end up making 13 monthly payments' worth per year instead of 12. This is mathematically equivalent to sending one extra monthly payment per year toward principal.
Biweekly payments work well if your income arrives biweekly and you want the payment to align with your paycheck. But they require your lender to accept them—not all do. Some lenders charge a fee to set up biweekly payments, which can offset the interest savings. Ask your lender whether they offer this option and whether there is a fee before switching.
If your lender does not offer biweekly payments, simply sending one extra monthly payment per year (or dividing it across twelve months as $100 extra per month) achieves the same result without the hassle.
What happens if you stop making extra payments
If you send extra payments for three years and then stop, you keep the benefit of those three years of reduced principal. Your loan does not revert to the original schedule. However, your monthly payment stays the same, so you will simply pay off the loan faster than originally planned—not as fast as if you had continued, but faster than if you had never sent extra payments at all.
This is why even small, inconsistent extra payments help. If you send $50 extra for two years, then $0 for a year, then $75 extra for another year, you still come out ahead of making only the required payment. The key is that every dollar sent to principal stays sent.
Frequently Asked Questions
Should I pay extra on my mortgage if I have not maxed out my 401k?
No. Retirement contributions usually come first because they reduce your taxable income and often include employer matching. Max out your 401k or IRA before sending extra money to your mortgage. After retirement savings are secure, extra mortgage payments make sense.
What if I have a very low mortgage rate, like 2.5 percent?
At rates below 3 percent, the interest savings from extra payments are small. If you have other financial goals—building emergency savings, funding a child's education, or investing—those may offer better returns. Extra mortgage payments still reduce your loan faster, but the urgency is lower than with a 6 percent mortgage.
Can I deduct extra mortgage payments on my taxes?
No. You can deduct the interest portion of your regular mortgage payment, but extra principal payments are not tax-deductible. This does not change the math of whether to make them—it just means the interest savings are the only benefit.
What if my mortgage has a prepayment penalty?
Some older mortgages charge a fee if you pay off the loan early or send large extra payments. Check your loan documents for a prepayment penalty clause. If one exists, calculate whether the interest savings from extra payments exceed the penalty. Often they do not, especially if the penalty applies to the entire remaining balance.
Is it better to refinance to a shorter loan term or make extra payments?
Extra payments give you flexibility—you can stop or reduce them if your situation changes. Refinancing to a 15-year loan locks you into a higher monthly payment. If you can afford the higher payment and plan to stay in the home, refinancing works. If you want the option to reduce payments later, extra payments on your current loan are safer.