What 28% usually means
The rule commonly compares monthly housing costs with gross monthly income. Depending on the version, housing costs may include principal, interest, property tax, insurance, and association fees.
Why your number may differ
Gross income is not spendable income. Taxes, childcare, healthcare, debt payments, maintenance, and irregular expenses can make a lower housing cost more comfortable. Lenders also use their own rules and documentation.
Stress-test the result
Consider higher rates, repairs, insurance increases, income changes, and the cash left after closing. A ratio that works only under the most favorable assumptions may not leave enough room for surprises.
Try your numbers
The Home Affordability calculator provides an estimate from the assumptions entered. It is not a lending decision or guarantee.
The 28/36 rule, in one table
The full version has two caps: housing at 28% of gross monthly income, and housing plus all debt payments at 36%. At $8,000 gross a month: $2,240 for housing, and all debts together under $2,880.
| Gross monthly income | 28% housing cap | 36% total-debt cap |
|---|---|---|
| $4,000 | $1,120 | $1,440 |
| $6,000 | $1,680 | $2,160 |
| $8,000 | $2,240 | $2,880 |
| $10,000 | $2,800 | $3,600 |
| $12,500 | $3,500 | $4,500 |
| $15,000 | $4,200 | $5,400 |
Common questions
- Is the 28% rule gross or net income?
- Gross — before tax. That is what makes it generous: 28% of gross can easily be 35–40% of take-home pay. Treat the rule as a ceiling for approval, not a target for comfort; your real limit should come from net income after saving.
- What is the difference between the 28% rule and the 28/36 rule?
- The 28% cap covers housing alone (principal, interest, tax, insurance). The 36% cap adds every other monthly debt payment — car, student loans, cards — on top. Lenders weigh both; the binding constraint is usually the 36% back-end ratio when other debts exist.
- Is the 28/36 rule still used by lenders?
- As a starting heuristic, yes — but actual approvals run through debt-to-income limits that are often looser (commonly 43–50% total DTI depending on the loan program). Being approvable for more than 28/36 does not make it affordable for your life.