Rent Budget Calculator (30% Rule)
Max affordable rent from income, with yearly cost and leftover budget.
What it does
The 30% rule is the rental twin of the mortgage 28%: households spending more than 30% of income on housing count as cost burdened in federal statistics. Landlords use the same line from the other side, often requiring income near three times the rent.
The tool above takes gross yearly income and returns the monthly cap, the yearly housing cost, and the leftover for everything else.
Gross versus net matters here. Thirty percent of gross can feel like forty of take home after tax, so tight budgets should run the rule on net pay too and compare.
Upfront cash decides as much as monthly rent. First month, deposit, broker fees, and moving costs often total three to four months of rent before the first night.
How to use
- Enter gross yearly income before tax.
- Read the monthly cap as the search ceiling.
- Check the leftover against real spending for a month.
- Add utilities and parking to rent before comparing listings.
Formula
- 0.30
- Federal cost burden line used by HUD.
- / 12
- Yearly income to monthly budget.
- leftover
- Monthly income minus rent for all other life.
The 3x rent income test inverts the same math: a $2,000 rent wants $72,000 yearly income (2,000 x 12 / 0.30). Some cities use 40x monthly rent, which equals the same 30% line.
Worked example
Example: $80,000 income
Yearly gross 80,000.
- Monthly income: 80,000 / 12 = $6,666.67.
- Max rent: 80,000 x 0.30 / 12 = $2,000.00 a month.
- Yearly on rent: 2,000 x 12 = $24,000.00.
- Leftover: 6,666.67 - 2,000 = $4,666.67 a month.
Reference table
| Income | Max rent | Leftover monthly |
|---|---|---|
| $40,000 | $1,000 | $2,333.33 |
| $60,000 | $1,500 | $3,500.00 |
| $80,000 | $2,000 | $4,666.67 |
| $120,000 | $3,000 | $7,000.00 |
Limits
- Gross income assumed. Net pay tells the tighter truth.
- Ignores debts, which shrink real room fast.
- Utilities and fees sit outside rent.
- Roommates and couples split differently than solo renters.
Common mistakes
- Budgeting gross while spending net.
- Forgetting utilities, parking, and renter insurance.
- Counting the deposit as rent instead of upfront cash.
- Signing at 40% and hoping spending bends.
- Ignoring commute cost against cheaper far rent.
Try it yourself
Quick checks. Answers sit tucked under each question.
$96,000 income. Max rent?
96,000 x 0.30 / 12 = $2,400 a month.
A $1,800 rent wants what income at 30%?
1,800 x 12 / 0.30 = $72,000 a year.
Questions
What is the 30% rule?
Spend at most 30% of gross income on housing. Past it, households count as cost burdened.
Why do landlords ask 3x rent?
It mirrors the rule: 3x monthly rent yearly equals 36x monthly, near the 30% line with margin.
Is 35% ever okay?
In expensive cities with no car costs, sometimes. It leaves thin room for savings shocks.
Gross or net income?
Listings use gross. Your budget should also pass on net, which runs 20 to 30% lower.
What counts as rent?
Base rent plus required fees, utilities you pay, and parking. Compare all in totals.
How much cash starts a lease?
Often first month plus deposit plus fees: two to four months of rent upfront.