Housing Cost Ratio Calculator

The "30% rule" — spend no more than 30% of gross income on housing — is a rule of thumb most people have heard but few actually calculate against their real, all-in costs. This calculator adds up rent or mortgage payment, property tax, homeowners or renters insurance, utilities, maintenance, and HOA fees into one Total Housing Cost, then divides that by gross monthly income to produce the Housing-to-Income Ratio the 30% rule is actually measuring — not just the mortgage or rent line by itself, which is the version most people mentally compare against the rule and consistently underestimate. It reports a straightforward Within 30% Rule? yes/no verdict, and translates the gap into concrete numbers: Recommended Max Housing shows what 30% of your income actually equals in dollars, and Monthly Overage shows exactly how far above that ceiling your real costs sit (floored at zero if you're under it), which is far more actionable than the percentage alone.

A few honesty checks matter here: property tax and maintenance are easy to forget or lowball since they aren't a single monthly bill the way rent is, and this calculator only knows what you enter — it doesn't infer maintenance from home value or pull real tax rates. The 30% threshold itself is also a general guideline, not a hard financial law; it originated from federal housing-assistance eligibility standards and doesn't account for your other debts, savings rate, or how much you're deliberately trading off in this budget category versus others. Treat the ratio as a useful benchmark for a conversation about affordability, not a pass/fail grade.