What is the 30% rule?

The 30% rule is a long-standing guideline that housing should consume no more than 30% of your gross income. Spending more than 30% on rent classifies you as cost-burdened in U.S. housing statistics, and over 50% as severely cost-burdened.

Should I use gross or net income?

The traditional 30% rule uses gross (pre-tax) income, and most landlords screen on gross income too. This calculator follows that convention. If you prefer a stricter test, enter your take-home pay instead and treat the ceiling as conservative.

How does my rent compare to Boston's median?

Boston's median one-bedroom rent runs about $2,800 per month. The tool shows your target rent relative to that figure so you can see whether you are paying above or below the typical Boston one-bedroom price.

Why do many landlords ask for 40x rent?

The 40x-rent rule means your annual income should be at least 40 times the monthly rent, which is mathematically the same as the 30% rule (rent times 12 is 30% of 40 times rent). The tool also reports this annual-income multiple.

Does this include utilities or fees?

No. The 30% rule applies to base rent. In Boston, add roughly $150 to $250 in utilities and budget for broker fees, which can equal one month's rent. Use the Boston comfortable salary calculator for a fuller picture.

Boston Rent Affordability Calculator

Before you tour an apartment in Boston, it helps to know whether the rent is realistic for your income. This calculator applies the standard 30%-of-income affordability rule, shows your exact rent-to-income ratio, and benchmarks the rent against Boston’s median one-bedroom price.

How it works

The 30% rule says rent should be at most 30% of gross income. Your affordable monthly rent ceiling is therefore:

affordable_rent = monthly_gross_income * 0.30

Your actual rent-to-income ratio for a given rent is:

ratio = monthly_rent / monthly_gross_income

A ratio at or below 0.30 is comfortable. Between 0.30 and 0.50 you are cost-burdened; above 0.50 you are severely cost-burdened. The equivalent landlord screening test, the 40x rule, requires annual income of at least 40 times the monthly rent — which is the same threshold expressed differently.

Tips and example

Suppose you earn $90,000 a year, or $7,500 a month. Your affordable rent ceiling is 30% of $7,500, which is $2,250. A $2,800 median one-bedroom would put your ratio at about 0.37 — cost-burdened, though common in Boston. To comfortably afford a $2,800 apartment under the 30% rule you would need roughly $112,000 a year. Remember to budget separately for utilities and Boston’s broker fees, which often equal a full month of rent up front.