Extra Mortgage Payments: How Much You Save and How to Do It
Extra mortgage payments shorten your loan and cut the total interest you pay, because every extra dollar that goes to principal stops accruing interest for the rest of the loan. On a $300,000 loan at 6.5% over 30 years, an extra $200 a month ends the loan about 7 years early and saves roughly $103,000 in interest. The catch is that the money only works if your servicer applies it to principal, and if your loan has no prepayment penalty. This guide shows the numbers, the methods, and the checks to make before you send a dollar.
TL;DR
- Extra principal payments save interest because they shrink the balance that interest is charged on. The earlier in the loan you make them, the more they save.
- On a $300,000, 30-year loan at 6.5%, $100 extra a month saves about $61,000 and 4 years. $200 extra saves about $103,000 and nearly 7 years.
- Tell your servicer in writing that extra funds go to principal. Otherwise they may be treated as an early payment on the next installment.
- Check your note for a prepayment penalty first. Most current loans have none, but some do.
- Biweekly payments work by creating one extra payment a year. You can copy that yourself for free, so skip any program that charges a fee.
Table of Contents
- Why extra payments work
- What extra payments save: worked numbers
- Before you pay extra: check for a prepayment penalty
- Make sure the money goes to principal
- Biweekly payments: the calendar trick, without the fee
- Other ways to accelerate payoff
- Paying a 25-year loan off in 15
- When extra payments may not be your best move
- Our perspective
- Run your own numbers
- FAQ
- Sources
Why extra payments work
A standard mortgage payment is fixed, but its split between interest and principal changes every month. Early on, most of it is interest. Our example loan ($300,000, 6.5%, 30 years) has a monthly principal and interest payment of $1,896.20. In month one, $1,625.00 of that is interest and only $271.20 reduces the balance.
That is amortization: interest is charged on whatever you still owe, so the balance falls slowly at first and faster later. Freddie Mac's explainer on amortization describes how your amortization table lays out every payment you will make.
An extra $200 in month one does not just reduce the balance by $200. It removes that $200 from every future interest calculation, for all the months the loan would otherwise have run. That compounding effect is why small amounts early carry so much weight, and why the same $200 in year 25 barely matters.
What extra payments save: worked numbers
We ran the same loan under several scenarios. These are our own calculations for a fixed-rate loan, principal and interest only, with every extra amount applied to principal starting in month one. Your rate, balance and term will give different results.
| Strategy | Payoff time | Total interest | Interest saved vs. baseline |
|---|---|---|---|
| Baseline, no extra | 30 years | $382,633 | None |
| $100 extra per month | 26 years | $321,639 | about $60,994 |
| $200 extra per month | 23 years, 1 month | $279,185 | about $103,448 |
| $500 extra per month | 17 years, 6 months | $202,874 | about $179,759 |
| 1/12 of the payment added monthly (13 payments a year) | 24 years, 2 months | $295,377 | about $87,256 |
| One extra full payment each year | 24 years, 4 months | $298,649 | about $83,984 |
First, the savings are not linear. Doubling the extra from $100 to $200 a month saved far more than the first $100 did in absolute terms, because the loan ends much sooner and the later, interest-light years disappear.
Second, the gap between a lump sum once a year and a monthly top-up is small. Paying early in the year matters a little. Paying consistently matters most.
Third, even a modest habit changes the picture. You do not need $500 a month to take years off a loan.
To run your own figures, plug your balance, rate and term into a loan calculator before deciding on an amount. The calculators at MetriqaHub are free and need no registration.
Before you pay extra: check for a prepayment penalty
Most mortgages allow extra principal payments, but your loan agreement is the final word. The CFPB notes that some loans can carry a penalty for paying off early, commonly in the first 3 to 5 years of the loan.
Federal rules limit this. According to Nolo's summary of the CFPB rules, which took effect on January 10, 2014, prepayment penalties are prohibited for most residential mortgages except under a few specific circumstances. A fixed APR is one of the conditions for a penalty to be allowed at all.
What to do:
- Find your note and your closing disclosure, and look for a prepayment penalty clause.
- If you cannot find it, call your servicer and ask: "Does my loan have a prepayment penalty, and does it apply to partial prepayments or only to full payoff?"
- Ask for the answer in writing if there is any penalty at all, then weigh it against the interest you would save.
If the note is unclear or the amounts are large, a housing counselor or a real estate attorney can read it with you.
Make sure the money goes to principal
This is where many borrowers lose the benefit. A payment larger than the amount due is not automatically applied to principal. The federal bank help site addresses this exact situation: a borrower sends double the monthly payment, intending the surplus to reduce principal, and asks how the bank should apply it. Servicers may instead treat surplus as a credit toward the next month's payment, which does not reduce the balance interest is charged on.
To avoid that:
- Use the principal-only option in your online portal if one exists, or the designated line on your payment coupon.
- If you pay by check, write "principal only" and your loan number on the memo line, and include a short note with the same instruction.
- Pay the regular installment first, then make the extra payment as a separate transaction so the two cannot be blended.
- Check your next statement. The principal balance should fall by the regular principal portion plus your extra amount. If it does not, contact your servicer in writing and ask for a correction.
After a mistake, you can file a complaint with the CFPB if the servicer does not fix it.
Biweekly payments: the calendar trick, without the fee
Biweekly payments mean paying half your monthly amount every two weeks. A year has 26 two-week periods, so you make 26 half-payments, which equals 13 full payments instead of 12. The entire benefit comes from that one extra payment, which is why Chase explains that you can get the same effect by adding a steady extra amount to your monthly payment or making one extra payment a year.
Our table shows the result: one extra payment a year on our sample loan saves about $84,000 and 5 years and 8 months. Spreading it over twelve months (the 1/12 method) does slightly better.
The 1/12 method
Divide your monthly principal and interest payment by 12 and add that amount to every monthly payment. On our $1,896.20 payment, that is about $158 extra a month. Freddie Mac describes the same approach and gives an example: on a $250,000, 30-year loan at 4.5%, it can shorten the term by roughly 5 years.
Watch for fee-based programs
Some third-party companies sell biweekly plans. The CFPB took action against one such company in 2015, alleging that it misled consumers about mortgage savings from a program that, for most customers, amounted to sending half the payment every two weeks. Enrollment fees on programs like these can run into the hundreds of dollars, which can wipe out much of what you save.
If your own lender offers a biweekly option, confirm three things before signing up:
- Is there any setup or per-payment fee?
- Are payments applied when received, or held until a full monthly amount accumulates?
- Can you cancel without penalty?
If any answer is unclear, the free alternative is simpler: set up a recurring extra principal payment yourself.
Other ways to accelerate payoff
You do not have to pick one method. These all work toward the same goal, and they combine well.
- Round up. If your payment is $1,896.20, pay $2,000. It is easy to automate and easy to forget.
- Apply windfalls. A tax refund, bonus or inheritance can go to principal as a one-time payment. The earlier in the loan, the better.
- Re-cast or refinance. Refinancing to a shorter term or a lower rate can shorten the loan, though closing costs matter. Our guide on calculating your refinance break-even shows how to tell whether the savings outweigh the costs.
- Remove PMI sooner. If you pay private mortgage insurance, extra principal brings you to the equity threshold faster. See how PMI works and how to stop paying it.
- Keep paying the old amount. If you refinance into a lower payment, keep sending the old payment. The difference goes straight to principal.
Paying a 25-year loan off in 15
To finish a loan in a shorter time, you need to pay what a loan with that shorter term would require. Take the new target term, calculate the payment for it at your current rate and balance, and subtract your current payment. The difference is your monthly extra.
A quick example using our loan: if you have a $300,000 balance at 6.5% and want it done in 15 years, the required payment is about $2,613, compared with $1,896.20 on a 30-year schedule. That is roughly $717 more per month. This is our own arithmetic, so run your actual balance and rate through a calculator.
When extra payments may not be your best move
Paying down a mortgage gives a guaranteed return equal to your interest rate, but it also locks cash into your house. A few situations call for a different order of priorities:
- You have no emergency fund. Home equity is hard to reach quickly. Build a cash buffer first, using the savings goal formula to set a target and timeline.
- You carry higher-rate debt. The same dollar usually does more good paying off a credit card. Our credit card interest formula guide shows how much that debt costs you each month.
- You are missing out on an employer retirement match. That is typically a better use of the next dollar.
- You may need the cash soon. Extra principal cannot be pulled back out without borrowing again.
If you are weighing these tradeoffs with a large sum, a fee-only financial planner can look at your whole picture.
Our perspective
We build calculators, so we see how people use them. The same pattern shows up with mortgage questions: most people ask, "how much can I save?" and few ask, "will my servicer apply it correctly?" The first question is math. The second is paperwork, and it decides whether the math ever happens.
We built MetriqaHub around the idea that a calculation should be instant, free and based on recognized standards, so you can test a scenario in seconds and decide with real numbers. Try three amounts rather than one. You will often find that the smallest extra you can sustain for years beats a large amount you stop after a few months.
Our advice is plain. Confirm there is no prepayment penalty, set up a recurring principal-only payment you will not notice, and check one statement to confirm it landed. Ignore anything that charges you to do what you can do for free.
— Nkosi
Run your own numbers
Every loan is different, so the figures above are a guide, not a forecast. Our free loan and mortgage calculators let you enter your balance, rate and term and compare payments with no sign-up. Test a few extra amounts, then take the one that fits your budget to your servicer.
FAQ
Do mortgages allow extra payments?
Most do. Extra principal payments are allowed on the majority of mortgages, but some loans carry a prepayment penalty, usually in the first few years. Read your note or ask your servicer before you start.
Is a biweekly payment plan worth paying for?
Not if it charges a fee. The savings come from making one extra payment a year, and you can do that yourself by adding to your monthly payment or sending one lump sum. If your own lender offers a free biweekly option, it can work as long as payments are applied promptly.
Does an extra payment go to principal automatically?
Not always. A servicer may treat surplus money as a credit toward your next installment. Specify "principal only" through your portal or in writing, then check the next statement to confirm your principal balance dropped.
How much extra should I pay each month?
Pay the amount you can sustain without draining your emergency fund or ignoring higher-interest debt. On a $300,000 loan at 6.5%, even $100 a month cuts about 4 years. Model a few amounts with a calculator, then automate the one you choose.
Sources
- Your mortgage servicer must comply with federal rules (CFPB)
- Mortgage Prepayment Penalties: What Borrowers Need to Know (Nolo)
- Does extra payment on my mortgage go to principal or interest? (HelpWithMyBank.gov)
- Understanding amortization (Freddie Mac My Home)
- Is There a Faster Way to Be Mortgage-Free? (Freddie Mac My Home)
- Biweekly vs. Monthly Mortgage Payments (Chase)
- CFPB Files Suit Against Nationwide Biweekly (CFPB)