Debt-to-income ratio: the number lenders check before your score

In this guide

How to calculate your DTI
Where 28/36 comes from
Actual DTI limits by loan type
What happened to the 43% rule
What counts as debt, including the edge cases
A worked case: one income, six different answers
What a monthly payment costs you in mortgage size
How to lower your DTI before applying
Frequently asked questions
Sources

Your debt-to-income ratio (DTI) is your monthly debt payments divided by your gross monthly income. The CFPB's own example is $2,000 of debt payments on $6,000 of gross income, a DTI of 33%. How high yours can go depends on the loan: Fannie Mae accepts up to 50% on loans run through its automated system, and the federal 43% cap on qualified mortgages no longer exists.

How to calculate your DTI

Add up every required monthly debt payment, divide by your income before tax, and multiply by 100. The CFPB defines gross income as what you earn "before your taxes and other deductions are taken out", which is why the ratio usually looks more comfortable than your bank balance feels.

Lenders often quote two versions:

Front-end (housing) ratio: the full housing payment divided by gross income. For a mortgage that means principal, interest, property tax, homeowners insurance, mortgage insurance, and any HOA dues, not just the loan payment.
Back-end (total) ratio: housing plus every other debt payment, divided by gross income. This is what "DTI" usually means.

Where 28/36 comes from

The 28/36 pair is a guideline published by the regulator, not a lending rule. The CFPB's Your home loan toolkit calls 28% of pre-tax income for the total monthly home payment "a mortgage lending rule of thumb" and says lenders may approve more or less. Its debt-to-income worksheet suggests homeowners keep total DTI at 36% or less, notes that some lenders go to 43% or higher, and suggests 15% to 20% for renters, with rent left out of that figure.

On $6,000 a month gross, 28/36 means $1,680 for housing and $2,160 for all debt.

Actual DTI limits by loan type

The real ceilings are set by each loan program. These are the published figures as of October 2026:

Loan type	Maximum DTI	Conditions
Fannie Mae, automated (Desktop Underwriter)	50%	Per the Fannie Mae Selling Guide B3-6-02
Fannie Mae, manually underwritten	36%, up to 45%	Above 36% only with the credit score and reserves in Fannie Mae's eligibility matrix
FHA, manually underwritten	31% housing / 43% total	Hard cap with no credit score or a score below 580
FHA, manual, score 580 or higher	37/47 or 40/50	One compensating factor for 37/47, two for 40/50, per HUD's 2013 manual underwriting notice
VA	41% benchmark	Above 41% needs written justification unless residual income beats VA's guideline by 20%, under 38 CFR 36.4340
General Qualified Mortgage	No fixed cap	The lender must consider and verify DTI or residual income

FHA compensating factors are a closed list in that notice, such as cash reserves or a new payment barely above your current housing cost. The FHA tiers come from that 2013 notice, so confirm with your lender that they still apply to your loan.

What happened to the 43% rule

Under the original ability-to-repay rule, a "General QM" loan could not have a DTI above 43%. The CFPB's General QM final rule, issued December 10, 2020, removed that limit and replaced it with a price test. After a CFPB delay announced April 27, 2021, the new definition became mandatory for applications received on or after October 1, 2022.

Under Regulation Z, 12 CFR 1026.43(e)(2), a first-lien loan at or above the base threshold of $110,260 (indexed each year) loses General QM status if its APR is 2.25 percentage points or more above the average prime offer rate. The lender must still consider and verify your DTI or residual income. So a 45% DTI loan can be a qualified mortgage today; the 43% figure you still see online is history.

A monthly budget worksheet beside a calculator and highlighters

What counts as debt, including the edge cases

Fannie Mae's rules in Selling Guide B3-6-05 spell out how lenders selling loans to Fannie Mae count each debt. FHA, VA, and other programs set their own rules, so treat this as the conventional-loan version.

Debt	How it is counted
Credit card	The payment on the credit report, not the balance. If no payment is reported, 5% of the balance: a $5,000 balance counts as $250 a month
Car loan, student loan, personal loan	Counted when more than ten payments remain. Ten or fewer can be left out unless, in Fannie Mae's words, the debt "significantly affects" your ability to pay
Car lease	Always counted, no matter how many months are left on the lease
Student loan in deferment or forbearance	1% of the balance, or a fully amortizing payment from the loan terms. A $40,000 deferred loan can count as $400 a month
Income-driven student loan plan at $0	Can count as $0 if the lender documents the $0 payment
Co-signed debt someone else pays	Can be excluded with 12 months of the other person's canceled checks or bank statements showing no late payments
Alimony and child support	Counted if payments continue for more than ten months
Utilities, groceries, phone bills, subscriptions	Not in the ratio. The CFPB worksheet counts loan and card payments plus court-ordered payments such as child support

When you apply for a mortgage, your current rent drops out of the math. The proposed housing payment on the new home takes its place.

A worked case: one income, six different answers

Gross income is $6,000 a month. Existing debts: a $450 car payment, a $280 student loan, and $70 of card minimums, so $800 a month, or 13.3% of income. Here is the most the full housing payment can be under each limit, computed as (limit times $6,000) minus $800, then capped by any housing ratio.

Maximum monthly housing payment on $6,000 gross income with $800 of other debt

Computed: limit times $6,000, minus $800, capped by the housing ratio where one applies. Limits from the CFPB, Fannie Mae Selling Guide, HUD 2013 notice and 38 CFR 36.4340.

The same borrower can be "maxed out" at $1,360 or approved at $2,200, an $840 a month gap, depending on the program. Under the 36% guideline the binding limit is the total ratio, not the 28% housing ratio: existing debt cuts the housing budget from $1,680 to $1,360.

What a monthly payment costs you in mortgage size

At 7.28%, the 30-year fixed average in Freddie Mac's survey for October 1, 2026, each $100 of monthly principal and interest supports about $14,615 of loan. That turns every existing debt payment into a dollar figure:

Monthly payment you carry	Mortgage principal it displaces at 7.28%, 30 years
$100	$14,615
$450 (the car payment above)	$65,769
$800 (all three debts)	$116,923

Model your own numbers in the loan calculator. Your own rate will differ from the average, and taxes and insurance also come out of the housing budget, so the real loan amount is lower than these figures.

How to lower your DTI before applying

Remove whole payments. Paying a car loan from $6,000 to $2,000 leaves the $450 payment in the ratio. Paying it off removes all $450. See the payoff math before draining savings to do it.
Pay an installment loan down to ten or fewer payments. Under Fannie Mae's rule that payment can drop out of the calculation, often for far less than a full payoff.
Document co-signed debt. If someone else has paid it for 12 months, collect their statements before you apply.
Get a real payment on deferred student loans. If your actual income-driven payment is lower than 1% of the balance, documenting it can lower the counted amount.
Do not add debt before closing. A new car payment between approval and closing can push you over the limit the approval was based on.

Paying down a credit card barely moves DTI, because only the minimum payment counts. It does move your score through utilization, which matters for the rate you are offered. See what credit score a mortgage needs.

Frequently asked questions

Is DTI based on gross or net income?

Gross income, before taxes and other deductions, per the CFPB's definition. A $6,000 gross salary with $2,000 of debt payments is a 33% DTI even though take-home pay is lower.

What is the maximum DTI for a conventional loan?

For Fannie Mae loans it is 50% when underwritten through Desktop Underwriter. Manually underwritten loans are capped at 36%, or 45% with the required credit score and reserves.

What is the maximum DTI for an FHA loan?

For manually underwritten FHA loans, 31% housing and 43% total is the standard, and borrowers with no score or a score below 580 cannot exceed it. With a 580 score or higher, HUD's 2013 notice allows up to 37/47 with one compensating factor and 40/50 with two.

Is 43% still the DTI limit for a qualified mortgage?

No. The CFPB replaced the 43% limit with an APR-based test, mandatory for applications from October 1, 2022. Lenders must still consider and verify DTI or residual income.

Does my credit card balance count or just the minimum?

The minimum payment shown on your credit report counts. If no payment is reported, Fannie Mae has lenders use 5% of the balance.

Do deferred student loans count in DTI?

Yes. Fannie Mae lenders use 1% of the balance or a fully amortizing payment, so a $40,000 deferred loan can add $400 a month.

Does a co-signed loan count against me?

By default it does. Fannie Mae lets the lender exclude it if the other borrower has made the last 12 payments on time and you can document it.

What if my income varies month to month?

Lenders must document that income is stable, has a history of receipt, and is likely to continue, per Fannie Mae Selling Guide B3-3.1-01. One strong month does not establish that history.

Sources

What is a debt-to-income ratio?, Consumer Financial Protection Bureau. Checked October 2026.
Your home loan toolkit, Consumer Financial Protection Bureau. Checked October 2026.
Debt-to-income calculator (Your Money, Your Goals), Consumer Financial Protection Bureau. Checked October 2026.
Selling Guide B3-6-02, Debt-to-Income Ratios, Fannie Mae. Checked October 2026.
Selling Guide B3-6-05, Monthly Debt Obligations, Fannie Mae. Checked October 2026.
Qualified Mortgage Definition: General QM Loan Definition, final rule, Consumer Financial Protection Bureau. Checked October 2026.
CFPB Delays Mandatory Compliance Date for General Qualified Mortgage Final Rule, Consumer Financial Protection Bureau. Checked October 2026.
12 CFR 1026.43, Minimum standards for transactions secured by a dwelling, Legal Information Institute. Checked October 2026.
FHA Risk Management Initiatives: New Manual Underwriting Requirements, U.S. Department of Housing and Urban Development (Federal Register). Checked October 2026.
Primary Mortgage Market Survey, Freddie Mac. Checked October 2026.
38 CFR 36.4340, Underwriting standards, processing procedures, lender responsibility, and lender certification, Legal Information Institute. Checked October 2026.

How this page was checked. Every figure was checked against the primary sources listed above, most recently on October 7, 2026. Drafting is AI-assisted; the research, the math, and the final edit are done by Teja Pagidimarri. Read the editorial policy, or report an error through the corrections page. This is general information, not personal financial advice.

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Teja Pagidimarri

Teja Pagidimarri built 43dots to answer money questions with numbers you can check. He is a software developer, not a licensed financial advisor, so every guide here is built the way an engineer would: figures pulled from the primary source, math shown in the open, and the calculators built from the actual published formulas.