28/36 Rule Calculator — Housing Affordability
The 28/36 rule is the standard US mortgage-qualification guideline: your monthly housing costs should not exceed 28 % of gross monthly income, and your total monthly debt payments should not exceed 36 %. Enter your income and monthly obligations to see where you stand.
Income period
Your housing costs exceed the 28 % guideline
- 1
Gross monthly income
75,000 ÷ 12 = 6,250 - 2
Max housing payment (28%)
6,250 × 0.28 = 1,750Housing costs (PITI) must not exceed 28% of gross monthly income. - 3
Max total debt (36%)
6,250 × 0.36 = 2,250
How does this calculator work?
Divide monthly housing costs by gross monthly income — the result should be ≤ 28 %. Divide all monthly debt payments by gross monthly income — the result should be ≤ 36 %. These are the conventional mortgage qualification benchmarks (2024 Fannie Mae / Freddie Mac guidelines, subject to change).
Formula
How this is calculated
Mortgage lenders use two debt-to-income ratios to assess how much house you can afford. The front-end ratio (also called the housing ratio) divides your total monthly housing costs — principal, interest, property taxes, and homeowner insurance (PITI), plus any HOA fees — by your gross (pre-tax) monthly income. The back-end ratio (total debt ratio) adds all other recurring debt minimums (car loans, student loans, credit card minimum payments) to the housing costs before dividing by income. Lenders typically approve conventional loans when the front-end ratio is at most 28 % and the back-end ratio is at most 36 %.
These thresholds date to guidelines established by Fannie Mae and Freddie Mac and remain the most common benchmarks for conventional conforming loans in the US. FHA loans are somewhat more lenient (typically 31 % / 43 %), and some automated underwriting systems allow higher ratios for borrowers with strong credit or large down payments. The 28/36 figures are 2024 conventional guidelines; they can change with market conditions or regulatory updates.
The calculator does not factor in credit score, down payment size, loan-to-value ratio, or reserve requirements — all of which affect real lender decisions. Use this tool as a quick first filter. If either ratio is above the limit, consider a smaller mortgage, paying down existing debts before applying, or increasing income.
Frequently asked questions
PITI stands for Principal, Interest, Taxes, and Insurance. It is the full monthly cost of owning the home: the mortgage principal and interest payment, property tax (usually 1/12 of the annual bill), homeowner insurance premium, and any private mortgage insurance (PMI) or HOA fees. Do not include utilities.
Gross income — your earnings before federal, state, and local taxes and before any deductions. This is the figure lenders use because it is verifiable from W-2s and pay stubs, and it is consistent across borrowers in different tax situations.
Lenders weigh both ratios. Exceeding only the back-end ratio is usually harder to fix (it requires paying down debts or earning more). Exceeding only the front-end ratio sometimes passes if the back-end ratio is well below 36 % and other compensating factors (credit score, savings) are strong. FHA guidelines allow front-end up to 31 % and back-end up to 43 %.
TG we-Calculate Editorial Team. (2026). 28/36 Rule Calculator — Housing Affordability [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/28-36-rule-calculator
TG we-Calculate Editorial Team. "28/36 Rule Calculator — Housing Affordability." TG we-Calculate. 2026. https://we-calculate.com/calculator/28-36-rule-calculator.
TG we-Calculate Editorial Team, "28/36 Rule Calculator — Housing Affordability," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/28-36-rule-calculator
@misc{wecalculate_28_36_rule_calculator, title = {28/36 Rule Calculator — Housing Affordability}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/28-36-rule-calculator}}, year = {2026}, note = {TG we-Calculate} }
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