There are two rent rules of thumb in circulation and they disagree with each other by a wide margin. Landlords and listing sites use “3x”: monthly rent should be no more than one-third of gross monthly income. Budgeting guidance — and the housing-cost-burden definition used by HUD — uses 30% of income, and the version worth following applies it to net income. The difference between the two is the tax layer, and it is large.
The 3x gross rule and why it is generous
On $100,000 gross, 3x says you can afford $2,778 a month. That is a landlord’s screening threshold, designed to protect the landlord; it does not consider that in San Francisco $100,000 nets $6,054 a month, so $2,778 would be 46% of what actually arrives. The 3x rule is a ceiling on what you will be allowed to rent, not a guide to what you should.
The 30%-of-net guideline
Thirty percent of net monthly pay is the guideline this site’s rent meter uses. Above 30% is classed as cost-burdened, above 50% severely so, following the convention HUD uses for gross income but applied to net, which is stricter. Below 25% we call comfortable. It is a guideline, not a law — someone with no car, no debt and no dependents can sustain more; someone with student loans or childcare less — but it is the right starting point because it is measured in the money you have, not the money the letter says.
What 30% of net buys in eight cities
| City | 1BR median | Max rent at $80K | at $100K | at $150K |
|---|---|---|---|---|
| New York City | $3,900 | $1,460 | $1,763 | $2,506 |
| San Francisco | $3,250 | $1,517 | $1,816 | $2,550 |
| Boston | $2,950 | $1,524 | $1,849 | $2,646 |
| Seattle | $2,050 | $1,603 | $1,949 | $2,798 |
| Chicago | $1,900 | $1,532 | $1,859 | $2,663 |
| Denver | $1,700 | $1,547 | $1,874 | $2,679 |
| Atlanta | $1,600 | $1,541 | $1,868 | $2,669 |
| Austin | $1,450 | $1,628 | $1,979 | $2,845 |
Read across a row and the tax layer shows: Austin’s $100,000 earner can afford $216 more rent than New York’s, before considering that New York rent is $2,450 higher. Read down a column and the verdict changes with the city: at $100,000, the median 1-bedroom is within the guideline in Austin (22% of net), Atlanta (26%), Denver (27%) and Chicago (31%, borderline); it is above 45% in San Francisco and Boston and 66% in New York City. At $150,000 the picture eases — Boston drops to 33%, San Francisco to 38% — but New York City is still at 47%.
Where the guideline breaks
In the three most expensive markets the 30% guideline is not achievable on a single income at or below $100,000 without a roommate, a studio, or a commute. That is not a failure of the guideline; it is information. A single renter earning $100,000 in New York City who takes the median 1-bedroom will spend two-thirds of their take-home on it and has $1,977 a month for everything else. The audit for that salary and city says so directly, and the “gross needed for 30% rent” figure on the page — roughly $236,000 in New York — is the salary at which the median 1-bedroom becomes a guideline-compliant choice.
How to use this with an offer
Take the salary, open its audit in the city you would live in, and look at three numbers: monthly take-home, the rent share the meter shows for the median 1-bedroom, and “left after rent.” If the share is above 40%, either the rent has to come down (share, studio, further out) or the salary has to go up, and the negotiation guide covers how to price that. If it is under 30%, the offer clears the largest single line in a renter’s budget, and the remaining question is what everything else costs in that city — which is a different question from the one this site answers.
Audits cited in this guide
Open the full paycheck breakdowns
About the figures in this guide
Every dollar amount above is produced by the same deterministic tax engine that generates the audit pages, using the published 2026 federal brackets and standard deduction, the 2026 Social Security wage base, each state's published schedule and each city's local tax rules. Assumptions: single filer, standard deduction, no dependents, no itemized deductions. Rent figures are median 1-bedroom asking rents refreshed quarterly. Read the methodology, or send a correction with a primary source.