When determining if a house in Webster Groves is truly affordable, calculating your debt-to-income in St. Louis is the most critical first step. The payment on the listing sheet looks fine. Then the lender runs debt-to-income and the purchase stops. DTI is not a personality score. It is monthly debts divided by gross monthly income, and different loan programs treat the same car lease and the same overtime very differently.
Sean Zalmanoff at Better Rate Mortgage starts most St. Louis second-opinion calls here, especially when the buyer is already pre-qualified somewhere else and shopping for a better structure. This article is education. It is not a rate quote and not a commitment to lend. Confirm the program and the automated underwriting findings on your application.
The definition, in one sentence
The Consumer Financial Protection Bureau explains DTI as your total monthly debt payments divided by your gross monthly income. Their worked example is $1,500 (housing) plus $100 (car) plus $400 (student loan), divided by $6,000 of gross monthly income, which is 33 percent. That is the shape of the math. It is not Better Rate Mortgage’s underwriting limit.
Gross means before taxes. Take-home pay is the wrong denominator. Housing in the top of the ratio is principal, interest, taxes, insurance, HOA or condo dues, and mortgage insurance when it applies. The bottom is qualifying income the program will actually count, not every dollar that hits your checking account.
What Fannie Mae will actually deliver
For conventional loans sold to Fannie Mae, Selling Guide B3-6-02 (Debt-to-Income Ratios, 2 Apr 2025) is the reference Sean uses in this conversation:
- Manual underwriting: maximum 36 percent DTI, or up to 45 percent when the loan meets the Eligibility Matrix compensating-factor rules
- Desktop Underwriter (DU): maximum 50 percent DTI
- If the ratio later recalculates above 45 percent on a manually underwritten loan, or above 50 percent on a DU loan, Fannie Mae says the loan is not eligible for delivery unless it is re-underwritten to an eligible finding
That is why a “we can go to 50” slide is incomplete. 50 percent is a DU ceiling, not a promise, and not the same as a manually underwritten loan. Overlays at the wholesale lender can sit below the guide.
The old Ability-to-Repay “Qualified Mortgage” 43 percent DTI cap was replaced by a price-based QM test in the CFPB’s December 2020 final rule (12 CFR 1026.43). Do not treat 43 percent as a legal maximum on every 2026 purchase. Do treat Fannie, FHA, and VA as separate ratio machines.
What belongs in the monthly obligation
Fannie Mae’s total monthly obligation is broader than “the mortgage and the car.” Installment debts, revolving minimums, leases, and other recurring obligations in B3-6-02 count. A lease payment typically counts even if you plan to turn the car in next year. Installment debts with fewer than 10 remaining payments can be excluded in situations the guide allows. Student loans have their own calculation methods when the payment on the credit report is zero or deferred.
What usually does not count as a debt in that ratio: utilities, cell phones, and groceries. What does count, and surprises St. Louis buyers: a HELOC minimum, a timeshare, child support, and a co-signed auto that still reports in your name if you cannot document that the other party has paid it on time.
Income has to be stable and documented. Overtime, bonus, and self-employment are averaged and tested. A one-month spike in a 1099 account does not rewrite the denominator. If the tax returns were built to show less income, conventional DTI may not be the right tool. That is a different product conversation, not a “we will just use bank deposits” shortcut on a Fannie purchase.
FHA and VA are not the Fannie table
FHA still teaches 31 percent housing and 43 percent total as the standard manual ratios, with room when compensating factors and TOTAL Scorecard support it. There is not a single public “FHA always allows X percent” ceiling you should write into a blog as a promise. HUD Handbook 4000.1 is the source; the specific finding on your case number is what matters.
VA is residual-income first. The 41 percent ratio is secondary. Residual that is at least 20 percent above the regional requirement, or other documented factors, can support a higher ratio with the right sign-off. If you are a veteran buying in St. Charles or South County, lead with residual, not with a conventional 50 percent talking point.
How to Fix a High Debt-to-Income in St. Louis
Pay down or pay off a revolving account that is lighting up the numerator, and keep the account closed if the underwriter needs it gone. Do not open a new car loan between pre-approval and closing. Raise the down payment only when it actually drops the housing piece enough to matter, and only when cash to close still works. Recast income correctly: a second job that has 12 to 24 months of history can help; a side hustle from last Tuesday cannot.
A price cut or a different house in Florissant versus Clayton can fix housing DTI faster than a lecture about “the market.” HOA dues on a condo are housing. A pretty monthly principal-and-interest quote that ignores the assessment is a lie you tell yourself.
If the ratio is still over the program after those moves, stop forcing conventional. Ask Sean whether a different occupancy, a different product, or waiting one more pay cycle is the honest path. Stretching DU to 50 percent because a listing agent is impatient is how closings miss.
What to send before you write the offer
Paystubs, W-2s, the credit report debts you know about, HOA or condo docs, and the full address. If you are self-employed, bring returns and a year-to-date profit and loss. If you already have a pre-qualification from another lender, send that too so Better Rate Mortgage can see which debts they counted.
Sean Zalmanoff, NMLS 239823, will review your debt-to-income in St. Louis to find the program you can actually close, not the one from a blog comment. Start at betterratemortgage.com.
Better Rate Mortgage, Company NMLS 2401335. Licensed where Sean originates. Educational only. Equal Housing Lender.
FAQ
Is 43 percent the legal maximum DTI in 2026?
No. The CFPB replaced the general QM 43 percent DTI cap with a price-based test. Fannie Mae DU still has a 50 percent delivery ceiling. Your loan can be tighter because of overlays.
Does my car lease count if I am done with it in eight months?
Lease payments typically count. Installment debts with fewer than 10 payments can be treated differently under Fannie Mae B3-6-02. Do not assume. Put the account on the table.
Can I use overtime to lower DTI?
Only if the program will average and count it. One strong month does not rewrite the denominator.
Why did another St. Louis lender say I was fine and now I am not?
They may have used a different program, ignored HOA dues, counted gross incorrectly, or skipped a debt that still reports. Bring both worksheets to Better Rate Mortgage.
Does a seller credit fix DTI?
A credit can change cash to close. It does not erase a car payment. If the ratio is the problem, you need a smaller housing payment, more countable income, or less monthly debt.
