What is the 3× rent rule?
The 3× rent rule is a simple screening guideline: the household's gross monthly income is at least three times the monthly rent. In other words, rent is about one-third of gross income when the household sits exactly at 3×.
The rule is a guideline, not a universal affordability law. It does not know your taxes, debt payments, transportation costs, childcare, insurance, utilities, deposits, or other living expenses. That is why ST Calculator shows the arithmetic clearly and also gives you a rent-to-income view rather than presenting one number as a complete budget.
🏠 Start with rent
Take the monthly rent and multiply it by the selected income multiple. At 3×, a $1,500 rent produces a $4,500 gross-income requirement.
💼 Use gross income
Screening rules commonly use gross income — before taxes and other payroll deductions. Your personal budget should also look at net income because that is what actually reaches your bank account.
👥 Share the requirement
If several tenants qualify together, the household requirement stays the same, while the calculator divides that requirement into an illustrative per-tenant share.
Why gross income and rent share both matter
A 3× calculation is quick, but a real affordability check needs context. Gross income can be useful for a consistent screening rule, while rent-to-income percentage shows the same relationship from the renter's side.
3× screening view
Budgeting view
3× rent formulas
The core arithmetic is deliberately simple. What changes is the question you ask of it.
- Required income
- the gross monthly income implied by the chosen multiple.
- Monthly rent
- the recurring rent amount used by the scenario.
- Multiple
- the income-to-rent threshold, with 3× as the default scenario.
- Maximum rent
- the rent ceiling implied by a given gross monthly income and multiple.
- Rent-to-income ratio
- the monthly rent divided by gross monthly household income, expressed as a percentage.
Worked examples
These examples show how the same 3× relationship can answer different rental questions.
$1,500 monthly rent
If the selected threshold is 3×, the household income requirement is $4,500 gross per month.
$6,000 gross monthly income
At a 3× threshold, the implied maximum monthly rent is $2,000.
$2,400 rent, two tenants
The household requirement is $7,200. If split evenly for illustration, that is $3,600 of gross income per tenant.
$1,800 rent, $5,000 income
The household is at about 2.78× income-to-rent. The rent consumes 36% of gross income, so it does not reach a 3× threshold.
How to use a 3× rent result responsibly
The calculator answers a screening question; your budget answers an affordability question. Before signing a lease, compare the rent with the money you actually take home and the fixed commitments you already have.
| Gross income | 3× max rent | Rent at 2.5× | Rent at 4× |
|---|---|---|---|
| $3,600 | $1,200 | $1,440 | $900 |
| $4,500 | $1,500 | $1,800 | $1,125 |
| $6,000 | $2,000 | $2,400 | $1,500 |
| $7,500 | $2,500 | $3,000 | $1,875 |
Real-world rental context
Rent is not only a number on a listing. The same monthly rent can feel very different depending on income, household size, taxes, utilities and other recurring costs. A real rental property also has a physical context: location, building type, access, services and maintenance all influence the overall housing decision.
Related rental and finance calculations
Use the 3× rule as one step in a broader rental decision. For a more detailed affordability check, continue with Rent Calculator to examine rent-to-income relationships, or compare longer-term housing choices with the House Affordability Calculator. If you're evaluating a loan rather than a lease, the Loan Calculator can show monthly repayment and interest costs.