Section 8 rent calculation: a worked example

A Section 8 voucher pays part of your rent, and the Section 8 rent calculation decides how much. You pay a base payment: about 30% of your monthly income after deductions. The voucher pays the rest of the rent plus utilities, as long as they stay within a limit. Above that limit, you pay every dollar over it.

That limit is the voucher limit for your area, officially the payment standard. It is the most rent and utilities together can cost for your number of bedrooms while you still pay only your base payment. It is not what the voucher pays.

What do you need to know first?

• Adjusted income: your yearly income minus a few set deductions.
• Base payment: the least you pay each month, usually about 30% of your adjusted income. The U.S. Department of Housing and Urban Development (HUD), the federal housing department, calls it the "total tenant payment."
• Voucher limit (payment standard): the limit described above. Your housing office sets one for each number of bedrooms.
• Gross rent: the rent to your landlord, plus a utility allowance if you pay the utilities yourself. A utility allowance is the housing office's set amount for your utility bills.
• Your share: what you actually pay toward rent and utilities: the gross rent minus what the voucher pays. It equals your base payment when the gross rent is within the voucher limit, and it is higher when the gross rent is above it.

Step 1: What counts as your income?

HUD's income rule counts money from all sources for every household member who is 18 or older, and for the head of household and spouse even if they are younger. It also counts some income for children that doesn't come from work, but not the pay children under 18 earn. Ask your housing office about anything unusual.

Our example household is one parent and two children under 18 in Allegheny County, Pennsylvania, which includes Pittsburgh. The parent earns $2,400 a month, which is $28,800 a year. That is under the county's 2026 limit of $29,800 for three people, so the family counts as extremely low income, the lowest of HUD's three income levels. Our guide to Section 8 income limits explains the levels.

Step 2: How do deductions make it adjusted income?

HUD's deduction rule takes set amounts off your yearly income. The main ones are:

• $500 for each dependent, such as a child under 18, in 2026;
• $550 if the head of household or spouse is 62 or older or has a disability, in 2026;
• medical costs for those older or disabled households, but only the part over 10% of income;
• child care costs that let someone work or go to school.

HUD raises the first two amounts every January, and its table of 2026 amounts lists them. These are HUD's newer rules, which every housing office must follow from January 1, 2027. Until then, some offices still use the older ones, such as $480 for each dependent and medical costs over 3% of income, so ask yours which it uses. A housing office may also add deductions of its own.

For our family, the two children are two dependents, and we assume no child care costs:

• Yearly income: $28,800
• Two dependents at $500: $1,000
• Adjusted income: $27,800 a year, or about $2,317 a month

Step 3: What is your base payment?

Your base payment is the highest of these amounts, under HUD's rule on what you pay toward rent:

• 30% of your monthly adjusted income;
• 10% of your monthly income before deductions;
• the part of a welfare benefit set aside for housing, in the few states that set one;
• your housing office's minimum rent, which can be up to $50 a month for vouchers.

For our family:

The highest is $695. That is the family's base payment. It is also what the family pays toward rent and utilities if the gross rent is within the voucher limit.

Step 4: What is the voucher limit?

HUD publishes fair market rents every year for every county and metro area. A fair market rent is HUD's estimate of what a typical modest apartment rents for there. The housing office then sets a voucher limit for each bedroom size anywhere from 90% to 110% of that rent, without asking HUD, as HUD's payment standard rule allows. Some areas use rents set for each ZIP code instead.

HUD's fiscal year 2027 fair market rents for Allegheny County, in effect from October 1, 2026:

The housing office decides how many bedrooms a family needs. Here, it gives our family a two-bedroom voucher. Its voucher limit for two bedrooms can be anywhere from about $1,250 to $1,528. We assume it chose 100%, so the voucher limit is $1,389. Ask your housing office for its own schedule. If you rent a smaller home than your voucher allows, the limit for the smaller home applies, under HUD's voucher payment rule.

Step 5: What does the voucher pay?

The voucher pays the lower of two numbers, under HUD's voucher payment rule:

1. the voucher limit minus your base payment: $1,389 − $695 = $694; or
2. the gross rent minus your base payment.

You pay the rest, which is your share, as HUD's family share rule says. For the same family at four different gross rents:

At $1,200, the second number ($1,200 − $695 = $505) is lower, so the voucher pays $505 and the family pays exactly its $695 base payment. At $1,400, the gross rent is $11 over the voucher limit, so the family pays $11 more. At $1,550 and $1,700, the voucher stays at $694 and the family pays everything above it.

What is the 40% limit?

When you first rent a home with the voucher, what you pay can't be more than 40% of your monthly adjusted income. That is HUD's rule on the most you pay at move-in. It only matters when the gross rent is above the voucher limit.

For our family, 40% of $2,317 is about $927. The $1,550 home passes, because the family would pay $856. The $1,700 home fails, because $1,006 is over $927. The highest gross rent that can pass is $694 plus $927, which is about $1,621. The housing office must also find the rent reasonable compared with similar homes nearby, under HUD's reasonable rent rule, so a landlord can't simply ask for any number.

What if you pay the utilities?

If you pay your own utilities, the housing office adds its utility allowance to your rent to get the gross rent. It uses its own set amount, not your actual bill, under HUD's utility allowance rule.

Say our family rents an apartment for $1,300 a month and pays its own utilities, and the housing office's allowance is $150. The gross rent is $1,450, so the voucher pays its full $694 to the landlord. The family pays the landlord the other $606 of the rent and pays its utility bills itself. Its share is $756: the $606 it pays the landlord plus the $150 utility allowance. The $150 is only an example, so ask your housing office for its utility allowance schedule.

What happens when your income or the rules change?

The housing office reviews your income and household at least once a year, under HUD's rule on rechecking income. Between reviews:

• If your income drops, ask for a new review. The office can say no if your adjusted income would fall by less than 10%. If it lowers your share, the change starts the first of the month after you reported it.
• If you get a raise at work, it usually isn't counted until your next yearly review, unless your rent was lowered earlier that year. Other income increases of 10% or more get a new review, though the office may skip it in the last three months before your yearly one.
• Report every change by the deadline in your housing office's rules. If you report on time, the office must give you 30 days' notice before a higher share starts. If you report late, it charges the increase back to the first of the month after the change.

If the housing office lowers its voucher limits, it must give you at least 12 months of written notice before your home is affected, under HUD's voucher payment rule.

Where do you go from here?

To run these numbers for your own household, try our Section 8 calculator. To find a voucher waitlist, the line of people waiting for a voucher, see our area-wide waitlists page or the Pennsylvania page. To see how vouchers work overall, read what Section 8 is, the requirements to qualify and how a waitlist opens. Our qualify check shows which listings fit your household.