Does a Car Payment Affect Your Mortgage? What a $79K Truck Really Costs
By Joe Nelson, Retired Air Force, Nelson Home Group Team Leader and Mortgage Loan Originator
Does a car payment affect your mortgage? Yes, and the hit is bigger than almost anyone expects. Your required monthly car payment goes into your debt to income ratio, and every dollar of it comes straight off the top of what your income can support. At the 6.5 percent modeling rate I use across this series, one dollar of monthly payment is worth about $158 of borrowing capacity. A $1,385 truck payment wipes out roughly $219,000 of it.
One honest note on that rate. 6.5 percent is a modeling number, not a quote. Freddie Mac’s national average was 6.69 percent on August 6, 2026, and it has run between 6.43 and 6.69 over the past six weeks. Those are baseline figures with no loan level price adjustments, so your real number moves with credit score, loan size, down payment, and property type.
Watch the full breakdown:
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How Much Mortgage Does a $1,385 Truck Payment Cost You?
A $1,385 truck payment wipes out about $219,000 of borrowing capacity.
About $219,000 of borrowing capacity. Here is the arithmetic. A $79,000 truck financed at 8 percent for 72 months costs about $1,385 a month. Each dollar of monthly payment supports roughly $158 of loan at 6.5 percent on a 30-year term, so $1,385 times $158 is about $219,000 of mortgage you no longer qualify for. Same income, same credit score, same job. Nobody at the dealership runs that math for you.
Read that as loan amount, not sticker price. Losing $219,000 of borrowing capacity does not translate one for one into $219,000 off the house you can buy, because your down payment, property taxes, homeowners insurance, mortgage insurance, and HOA dues all sit in the same monthly payment. On a Kansas City file the practical result is usually a smaller drop in price and a much smaller pool of houses. It is still the most expensive fifteen minutes most buyers spend before they ever talk to a lender.
Here is what the trade looks like at other payment sizes.
| Monthly car payment | Borrowing capacity it replaces |
|---|---|
| $250 | about $39,600 |
| $400 | about $63,300 |
| $500 | about $79,100 |
| $750 | about $118,700 |
| $1,000 | about $158,200 |
| $1,385 | about $219,100 |
Illustration only, based on a 30-year principal and interest payment at a 6.5 percent modeling rate. This is loan amount, not purchase price, and it is not a rate quote or an approval. Run your own numbers on my mortgage calculator.
Which Car Payments Can a Lender Leave Out of Your Debt to Income Ratio?
A lease counts no matter how few months are left on it.
A few, and the rules are more specific than the internet version of them. On conventional files, Fannie Mae’s debt guidelines allow an installment loan with 10 or fewer monthly payments remaining to be left out, but it can still be counted if the payment significantly affects your ability to meet your obligations. A lease is different: it counts as a recurring monthly debt no matter how few months are left on it. If a credit card shows a balance but no required minimum payment, the lender has to use 5 percent of the balance unless you can document a smaller one. And a debt someone else actually pays can come out of your ratio if you produce 12 months of canceled checks or bank statements from that person showing no late payments.
VA files run on the same debt list plus a second test, residual income, which looks at what is left after the house payment, the debts, taxes, and basic living costs. A car payment can pass the ratio test and still squeeze residual. That test gets its own breakdown.
In the Kansas City files I work, the house payment usually lands somewhere between 25 and 35 percent of gross income with another 10 to 15 percent stacked on top in car payments, cards, and student loans. That is my file experience, not a published market statistic, and the full income ladder behind it lives in my Kansas City affordability guide. The income side of that ladder gets its own breakdown too.
How Should You Position Your Debts Six Months Before Buying?
If a home purchase is six to twelve months out, three moves protect your buying power.
- Finance nothing new. No truck, no furniture plan, no zero percent anything. The required payment counts no matter what the interest rate is, so a zero percent loan damages your qualifying exactly as much as an 8 percent one with the same payment.
- Pull your own credit report and write down every required monthly payment. You want to know your stack before a lender tells you what it is.
- Have a lender model your payoff options before you spend a dollar. The best debt to kill is usually the one with the largest payment relative to its balance, not the largest balance, and the only way to know is to run both versions of the file.
Should You Pay Off the Car Before Buying a House?
Buy the house first, then the truck.
Sometimes, and sometimes not. Paying off a loan with only a few payments left can free the whole payment for qualifying, which is cheap buying power. Draining your savings to kill a big loan right before closing can hurt worse than the payment did, because cash to close and reserves are part of the file too. And financing a car in the middle of the mortgage process is the classic self-inflicted wound. The new payment shows up on a credit refresh, the ratio moves, and the approval can die a week before closing. I have watched it happen to a buyer who had already picked out furniture.
Buy the house first, then the truck. If you are deciding between the two right now, that is a fifteen-minute conversation. Veterans should also know how VA’s residual income test treats those payments, and if part of your income is tax-free disability compensation, a lender can gross it up for the debt to income calculation, though not for the residual income test. Both tests still have to pass on their own.
Frequently Asked Questions
How much mortgage does a $500 car payment cost you?
About $79,000 of borrowing capacity. At a 6.5 percent modeling rate on a 30-year loan, each dollar of required monthly debt payment supports roughly $158 of mortgage, so a $500 payment replaces about $79,100 of loan amount. That is loan amount, not purchase price, and it is an illustration rather than a rate quote.
Do car leases count against mortgage approval?
Yes. Fannie Mae requires lease payments to be counted as a recurring monthly debt regardless of how many months are left on the lease, which is different from an installment loan. You cannot run out the clock on a lease the way you can on the last few payments of a car loan.
Can a lender ignore my car payment if the loan is almost paid off?
Sometimes. Fannie Mae allows an installment debt with 10 or fewer monthly payments remaining to be excluded, but the lender can still count it if the payment significantly affects your ability to meet your obligations. Have your lender confirm it on your file before you count on that money.
Does a zero percent car loan still hurt my mortgage approval?
Yes. Underwriting looks at the required monthly payment, not the interest rate, so a $500 payment at zero percent reduces your borrowing capacity exactly as much as a $500 payment at 8 percent. The dealership’s rate promotion does not follow you to the mortgage file.
Does a co-signed car loan count in my debt to income ratio?
Generally yes. If the loan reports on your credit, the payment counts. Fannie Mae will let it come out of your ratio when you document 12 months of canceled checks or bank statements from the other party showing they made the payments on time.
Should I buy a car before or after buying a house?
After, almost every time. A new car payment during the mortgage process changes your debt to income ratio and can kill an approval days before closing. Close on the house first, then go truck shopping.
Ready to Talk?
I make this content because I actually want to work with you. If you’re running this math on your own situation, don’t guess. Call me or shoot me an email and we’ll run your real numbers in one conversation.
Call: (816) 680-6624
Email: [email protected]
Web: https://nelsonhomegroupkc.com/
Joe Nelson is a licensed Realtor and mortgage loan originator serving the Kansas City metro. This article is for educational purposes and is not a loan commitment, a rate quote, or tax advice. Payment and qualifying figures are illustrations based on the assumptions stated above and will differ on your file. Equal Housing Opportunity.