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The 28/36 rule, with real numbers
Updated October 28, 2026 · Numbers from our calculators at October 2026 rates
The 28/36 rule is the most common guideline for how much of your income should go to a home. It has two limits, both measured against gross monthly income, before taxes:
28% for housing. The mortgage payment plus property tax, home insurance, mortgage insurance (PMI) and HOA dues should stay at or under 28% of gross income. Lenders call this the front-end ratio.
36% for all debts. That housing payment plus every other monthly debt payment, such as car loans, student loans and credit card minimums, should stay at or under 36%. This is the back-end ratio, usually just called debt-to-income.
Worked example
The 28/36 rule on a $100K salary
$100,000 a year is $8,333 a month. 28% of that is $2,333 for housing, and 36% is $3,000 for all debts.
With $500 a month in other debts, the 36% limit leaves $2,500 for housing, so the 28% limit is the tighter one. At about 7.35% for a 30-year loan with 10% down, a $500-debt household on $100K can afford a home of about $292,000, with a housing payment of $2,329.
Raise the other debts to $1,200 a month and the 36% limit takes over: the same income then supports only about $225,000. That is the rule's main job: once you carry other debts, every dollar of those payments comes out of the house.
By income
What the 28/36 rule allows
With $500 a month in other debts, 10% down and a 30-year loan at 7.35% (October 2026). The payment allowed is 28% of income, or less where other debts make the 36% limit tighter. Real monthly cost adds an upkeep reserve the rule leaves out.
What it leaves out
What the 28/36 rule doesn't count
The rule only counts payments a lender sees. Owning a home also takes upkeep: roofs, heating and cooling, appliances and repairs typically run about 1% of the price a year, or $243 a month on a $292,000 home. Utilities often rise too when you move from renting to owning.
Add upkeep and the household above spends about $2,572 a month, 31% of gross income, not 28%. The rule is a good ceiling for the payment, not for the full cost of owning.
Lenders
How lenders use it
Lenders use the same two ratios but often allow more. Many approve total debt payments up to about 43% of gross income, some go to 50% with strong credit and savings, and FHA loans use 31% and 43% as standard guidelines. Being approved for more doesn't make it comfortable: at 43%, a $100K household would carry about $3,583 a month in debt payments before upkeep, saving or anything else.
A stricter version, 25% and 33%, leaves more room for saving, retirement and childcare.
Questions
Common questions
Is the 28/36 rule based on gross or take-home pay?
Gross pay, before taxes and deductions. That is how lenders measure it, which is one reason 28% of gross can feel like a much bigger share of a take-home paycheck.
Does the 28% include property tax and insurance?
Yes. Housing means the full payment: principal, interest, property tax, homeowners insurance, mortgage insurance if you pay it, and HOA dues.
Can I go over the 28/36 rule?
Lenders often allow it, up to about 43% of income for all debts and sometimes more. Whether you should depends on your other goals; the real monthly cost, with upkeep included, is the number to check.
Try it
Run the 28/36 rule on your numbers
The home affordability calculator applies 28/36 by default, shows what 33% and 43% would allow, and adds the costs lenders leave out.