How much rent can you afford?
A common budgeting guideline says rent should stay under 30% of gross income. The calculator turns your pay into a monthly rent ceiling, then checks it against the HUD Fair Market Rent of every county. It shows the counties where a one- or two-bedroom apartment fits under the ceiling, the share of counties that qualify, and, if you pick a county, exactly how its rent compares with your pay and with local household income.
Where the 30% rule comes from
The 30% figure dates from United States housing policy in the 1980s, and HUD still uses it to define a household as cost-burdened when housing takes more than 30% of income. It is a screening rule, not a law of nature. Renters who spend over half of their income on housing are considered severely burdened. Many landlords also ask for income of about three times the monthly rent, which works out to a similar share.
Gross pay versus take-home pay
The guideline uses gross income, but rent is paid from take-home pay. A renter who earns $60,000 in a state with no wage tax and pays 30% of gross is committing $18,000 a year, about 36% of take-home pay. For that reason the calculator also shows rent as a share of take-home pay for the county you choose, which is the number that decides how tight a monthly budget feels.
What Fair Market Rent measures
HUD sets Fair Market Rent each year from Census survey data and local rent surveys. It represents the 40th percentile of gross rents for standard-quality units in an area, including basic utilities, so a typical available apartment is cheaper or about equal and a newer or better-located one is more expensive. It is a reliable county-level benchmark, but it is not a listing price, and rents in a few popular neighborhoods can sit well above the county figure.
The results list the largest counties where the rent fits, because the biggest counties are where most people are looking for work. Use the state filter to narrow the list to the region you are considering, and switch between one and two bedrooms to see how the number of qualifying counties changes.
Using the results
If your county does not fit, there are three levers: a higher income, a roommate, which splits a two-bedroom, or a different county. The county affordability and comparison calculators show the effect of the last one on your whole budget instead of rent alone.