Formulas
Gross monthly income = annual income ÷ 12, or hourly pay × hours/week × working weeks/year ÷ 12.
Rent-only benchmark = max(0, gross monthly × benchmark percentage − non-rent housing costs).
Cash-flow rent ceiling = take-home pay − debt − essentials − savings target − non-rent housing costs.
Move-in cash = rent due + deposits + fees + last month’s rent + pet rent + moving/setup − credits, with cash due floored at $0.
Scope, assumptions, and limitations
The 30% total-housing figure is a comparison benchmark, not a legal limit or landlord approval. The 25% comparison is an editorial planning reference.
Take-home pay is optional. No tax rate is invented when it is blank. A negative cash-flow ceiling or remaining budget is preserved as a shortfall.
Calendar proration includes the move-in day and all days through month-end. The 30-day convention uses a 30-day month and treats the 31st as day 30. Your lease may use another method; custom amount is available.
Credits are capped at modeled costs for cash due. Extra credits are reported without assuming a refund. Utility deposits are included in setup costs and may be refundable under their own terms.
Confidence and precision
Calculations retain precision until display formatting. The input-quality indicator is based on your classification of the source groups, not whether a field happens to contain a value. It does not measure the probability that a future outcome will match the estimate.
Example inputs are for learning the tool. Replace them with your own values, and compare a less favorable scenario to understand sensitivity.
Primary sources
HUD USER: Worst Case Housing Needs — definitions ↗
Undated definitions · Checked September 5, 2026
Methodology version 1.0 · Reviewed September 5, 2026.