What is a debt-to-income ratio on a mortgage?

The short answer: Your debt-to-income ratio (DTI) is all your monthly debt payments divided by your gross monthly income. Lenders use it as one measure of whether you can manage the payments on a loan you want to borrow. Different loan products and lenders set different DTI limits.^[1] Under the federal ability-to-repay rule, a creditor generally must consider your monthly DTI or your residual income, among other factors.^[3]

How do I calculate DTI?

The CFPB’s method: add up your monthly debt payments, then divide by your gross monthly income (generally income before taxes and other deductions).^[1]

Example from the CFPB: if you pay $1,500 for a mortgage, $100 for an auto loan, and $400 for other debts, monthly debts are $2,000. If gross monthly income is $6,000, DTI is 33 percent ($2,000 ÷ $6,000).^[1]

Are there legal DTI caps?

The CFPB says different loan products and lenders have different DTI limits.^[1] That is product- and lender-specific underwriting, not a single nationwide percentage you can treat as “the” legal limit for every mortgage.

Do not treat “28/36” as federal law. You may see 28/36 as a rule of thumb. It isn't a federal legal limit. Always use the limits your Loan Estimate and lender disclosures describe for your loan.

How DTI fits ability-to-repay and qualified mortgages

Regulation Z § 1026.43 generally requires a creditor not to make a covered dwelling-secured loan unless it makes a reasonable, good-faith determination that you can repay according to the terms. In making that determination, the creditor must consider a listed set of factors that includes your monthly debt-to-income ratio or residual income.^[3]

For a loan to be a Qualified Mortgage, the CFPB says the lender must consider and verify current monthly income or assets (other than the securing property’s value) and monthly debt, and must consider either your DTI or your residual income.^[2]

Separately, the Bureau’s December 2020 General QM final rule removed the General QM definition’s prior 43 percent DTI limit and replaced it with price-based thresholds. Compliance with those General QM amendments is mandatory for applications received on or after October 1, 2022.^[4]^[5] So “43 percent” is not the current General QM test for loans under the amended rule, even though older materials and some conversations still mention it.

For more on ability-to-repay and QM basics on this site, see Ability to repay and QMs, explained.

What this page does not do

It does not invent Fannie Mae, Freddie Mac, FHA, VA, or USDA DTI caps for 2026.
It does not say whether you will qualify for any loan.
It does not rank lenders or products.

FAQ

What is a debt-to-income ratio?

The CFPB defines DTI as all your monthly debt payments divided by your gross monthly income.^[1]

How do I calculate mine?

Add monthly debt payments and divide by gross monthly income. The CFPB’s example: $2,000 debts ÷ $6,000 income = 33%.^[1]

Is there one federal maximum DTI for all mortgages?

No. The CFPB says different products and lenders have different DTI limits.^[1] ATR requires considering DTI or residual income; it does not replace lender program rules with a single public percentage on this page.^[3]

Does a Qualified Mortgage still require DTI at or below 43%?

Not under the current General QM definition. The Bureau’s final rule removed that 43% General QM DTI limit and replaced it with price-based thresholds, mandatory for applications on or after October 1, 2022.^[4]^[5] QM still requires the lender to consider DTI or residual income.^[2]

Should I use 28% and 36% as legal limits?

No. You may see 28/36 as a rule of thumb. It isn't a federal legal limit.

This guide is general information, not legal or financial advice.