Lenders use the 28/36 rule as the starting framework: housing costs no more than 28% of gross monthly income, total debt no more than 36%. FHA is more flexible. Here's how the rules actually work.
This is general educational content about the underwriting frameworks lenders use to evaluate mortgage affordability. It is not personalized financial advice. Your actual approval amount depends on factors lenders evaluate individually — income, credit profile, debt obligations, down payment, and the specific loan program.
When a buyer asks 'how much home can I afford?' the honest answer starts with a question the lender is going to ask first: what does your gross monthly income look like relative to your debt obligations? Lenders translate that question into DTI ratios — front-end and back-end — and compare them against program-specific thresholds. Brian's video above walks through the salary-to-home-price framework. This editorial layer adds the official underwriting benchmarks so you know exactly which numbers lenders are measuring against.
The 28/36 rule is the standard conventional-lending benchmark, endorsed by CFPB and HUD guidance. It has two parts:
Example: a household with $8,000/month gross income would target a housing payment at or below $2,240 (28%) and total monthly debt at or below $2,880 (36%). If that household carries $600/month in car and student loan payments, the maximum housing payment consistent with the 36% ceiling is $2,280 — close to the front-end limit but not over it.
FHA loans — backed by the Department of Housing and Urban Development — use a slightly different threshold: 31% front-end and 43% back-end DTI. FHA also allows lenders to approve borrowers above the 43% back-end ceiling with documented compensating factors.
HUD Handbook 4000.1 lists compensating factors that allow FHA approvals above the standard DTI thresholds: verified cash reserves (at least 3 months' PITI), no discretionary debt (minimal credit card balances), residual income (income remaining after all obligations), or a minimal payment increase over the prior housing expense. These are lender-evaluated — not automatic approvals.
The CFPB's Qualified Mortgage (QM) rule establishes a 43% back-end DTI hard ceiling for standard QM loans. Lenders originating QM loans get a legal 'safe harbor' — a presumption that the loan meets the ability-to-repay standard. Loans above 43% DTI can still be originated, but the lender takes on more legal and regulatory exposure. In practice, most conventional lenders treat 43% as a functional ceiling for standard purchase mortgages.
DTI ratios tell you what a lender will approve. They don't tell you what you should spend. Four factors that shift the practical affordability picture well beyond the ratios:
The number a lender approves is a ceiling, not a recommendation. The right number for your situation depends on what's below the ceiling: your reserves, your income stability, your other financial goals.
Lenders evaluate whether you CAN service a loan. The question of whether you SHOULD take on that payment at that price — given your income stability, savings goals, childcare costs, and lifestyle — is a personal finance question that DTI ratios don't answer. Many buyers who are approved for the maximum find themselves house-rich and cash-flow-stressed within two to three years of purchase.
ClearValue Lending's mortgage affordability tools let you model the 28/36 and 31/43 frameworks against your own income and debt inputs — so you can see where you land relative to each threshold before talking to a lender. Use the tools hub to run the affordability estimate, or go directly to the mortgage matcher to see which programs fit your profile. We are not a mortgage lender or broker — we're an educational platform that routes to lender partners who can provide actual program details.
The 28/36 rule is the standard conventional-lending benchmark for mortgage affordability. The front-end ratio (28%) caps monthly housing costs — principal, interest, taxes, and insurance — at 28% of gross monthly income. The back-end ratio (36%) caps total monthly debt — housing costs plus all other recurring obligations — at 36% of gross monthly income. It's a guideline, not a law; individual lenders and loan programs may apply different thresholds.
DTI stands for debt-to-income ratio. Front-end DTI is your monthly housing costs divided by your gross monthly income. Back-end DTI is all your monthly debt payments (housing + credit cards + auto + student loans + other recurring debt) divided by gross monthly income. Lenders typically calculate both and compare them against program-specific thresholds.
Yes. FHA's standard thresholds are 31% front-end and 43% back-end — slightly more flexible than the conventional 28/36 benchmark. Additionally, FHA allows lenders to approve borrowers above the 43% back-end ceiling when documented compensating factors are present (strong cash reserves, minimal discretionary debt, or residual income above HUD's threshold). Lenders evaluate compensating factors on a case-by-case basis — they are not automatic.
Property taxes and HOA fees count in the front-end DTI calculation — they're part of the monthly housing cost (PITI). High property-tax markets (New Jersey, Illinois, Connecticut average over 2% of assessed value annually) meaningfully raise the front-end ratio at any given price point. HOA fees in condo or planned-development markets can add $400–$800/month. Both are often underestimated during the search stage and should be included in any realistic affordability model.
The CFPB's Qualified Mortgage (QM) rule under Regulation Z sets a 43% back-end DTI ceiling for standard QM loans. Lenders making QM loans receive legal protection (a 'safe harbor') from ability-to-repay challenges. Loans above 43% DTI can be originated outside QM, but lenders bear more regulatory and legal risk. In practice, most conventional lenders treat 43% as the functional ceiling for standard purchase mortgages.