Result
- 30% rule30% of gross monthly income = 30.0% of gross.$1,800.00
- 40× rule (NYC standard)Annual income ÷ 40 = $72,000.00 ÷ 40. Common landlord screen.$1,800.00
- DTI 36% rule36% gross − $400.00 in existing monthly debt. The CFPB-style total-debt rule.$1,760.00
- Recommended (most conservative)min(30% rule, DTI rule). Leaves room for savings + emergency fund per typical financial-planning guidance.$1,760.00good
- Stretch (if employment is stable)35% of gross — only sustainable with strong job security and no other major debt.$2,100.00
How to use this calculator
- Enter your monthly income — gross (pre-tax W-2) is preferred since the standard rules are written against gross.
- Enter existing monthly debt payments (car, student loans, credit card minimums) — this is needed for the DTI rule.
- Pick a rule of thumb for the primary number. The breakdown shows all three side by side.
- Use the recommended figure for your search ceiling; treat the stretch figure as a maximum only if your job is very stable.
About this tool
The 30% rule is the most widely-cited rent guideline: housing should consume no more than 30% of your gross monthly income, leaving 70% for taxes, savings, transportation, food, and discretionary spending. The 40× rule is what New York City landlords use: your annual income should be at least 40× the monthly rent. The DTI rule (used by mortgage underwriters and adapted here) caps total debt obligations including housing at 36% of gross. This calculator shows all three, plus a "recommended" figure that takes the most conservative of the 30% and DTI rules.
What this calculator does
Calculates the maximum rent you can afford based on your gross income using the standard "30% of gross income" rule that landlords and lenders apply for underwriting. Also shows the tighter 25% rule and the strict 20% rule for people with high other-debt loads or aggressive savings goals.
How it works — the formula
Max rent (30% rule) = gross monthly income × 0.30
Max rent (25% rule) = gross monthly income × 0.25
Max rent (20% rule) = gross monthly income × 0.20The 30% rule is the industry-standard rental affordability threshold, dating from HUD-defined "housing cost burden" (over 30% of income considered "cost-burdened"). The 25% and 20% versions provide tighter budgets for renters with student loans, other debt, or long-term savings priorities.
Worked examples
- Inputs:
- gross monthly income = $5,500
- Output:
- Max rent 30% = $1,650; max rent 25% = $1,375; max rent 20% = $1,100
A single renter earning $66K/year should target the 25%%-30%% band ($1,375-$1,650). The 20%% level ($1,100) preserves aggressive savings capacity.
- Inputs:
- combined gross monthly = $12,000
- Output:
- Max rent 30% = $3,600; max rent 25% = $3,000; max rent 20% = $2,400
In San Francisco, NYC, or Boston metros, a $3,600/mo rent on $144K gross is roughly the middle-market apartment. Below that requires location or size trade-offs.
Where the 30% rent rule comes from
The "30% of income for housing" rule was codified in US federal housing policy in 1969. Prior to that, HUD used a 25% threshold; the Brooke Amendment of 1969 raised the maximum public-housing rent to 25% of adjusted income, later increased to 30% via the Housing and Community Development Act of 1981. The 30% figure has since become the informal industry standard for defining rental affordability across the private market.
US Census Bureau data classifies households paying more than 30% of gross income on housing as "housing cost-burdened" and more than 50% as "severely cost-burdened". Cost-burdened households have systematically higher rates of eviction, food insecurity, and inability to save for retirement or emergency funds. About 21 million US renter households (roughly half of all renters) are currently cost-burdened per the 2022 American Community Survey.
30% vs 25% vs 20% — which rule to use
The 30% rule is a maximum, not a target. Financial planners increasingly recommend the tighter 25% band for renters who want meaningful savings capacity, and 20% for renters aggressive about student loan payoff or early retirement (FIRE) goals.
Household-specific factors argue for tighter budgets: high other-debt payments (student loans, credit card debt), single-income households with dependents, career instability, high-cost-of-living metros where all other expenses are also elevated, aggressive retirement or investment goals.
Some renters can safely push above 30%: no other debt, dual income, low-cost living metros, high job stability, roommates or partners sharing rent. In San Francisco or Manhattan, 35-40% of gross for rent is common because market rents exceed the 30% band for most incomes — which is one indicator these markets are structurally unaffordable, not that residents are budgeting poorly.
What "rent" actually includes
The 30% rule refers to housing cost, not just base rent. A complete housing budget includes: base rent, utilities (electric $50-200, gas $30-100, water $30-80, internet $50-100 typical), renter's insurance ($15-30/mo — universally worth having), parking ($0-500 depending on city), amenity fees (gym, pool, concierge — $50-200 in luxury buildings), and pet rent ($25-75/pet/mo).
On a $1,500 base rent, a realistic all-in housing cost typically runs $1,700-2,000/mo once utilities and insurance are included. Verify what utilities are included in the lease before signing — some landlords include water and trash but not electric; others include heat but not cooling.
How landlords verify income
Most landlords require gross monthly income to be at least 3x the base rent (equivalent to the 33%% rule — slightly looser than 30%%). Verification typically involves recent pay stubs or an offer letter, W-2s or tax returns for self-employed applicants, and bank statements showing consistent deposits.
For applicants with credit issues or non-traditional income (freelancers, gig workers, students), landlords often require: a guarantor with 5-6x rent income and good credit, extra security deposit (2-3 months rent instead of 1), or last month rent paid up front. Understand these before applying so you can prepare documentation.
When renting beats owning
The classic assumption that "renting is throwing money away" is often wrong. Renting is economically superior to owning when: you might move within 5-7 years (transaction costs on home sale run 6-10%% and typically exceed 5 years of "equity building"), local price-to-rent ratios exceed 20 (housing costs of ~$3,600/mo for a $500K home suggest renting is cheaper), your career or family situation is uncertain, or you want the psychological benefit of not being responsible for major repairs.
Renting is worse than owning when: you plan to stay 10+ years and prices appreciate steadily, price-to-rent ratios are below 15, you have stable dual income, and you can absorb ~1-3%% of home value annually in maintenance and repairs. These conditions are unusually well-suited to the "buy and hold" strategy that made previous generations of homeowners wealthy.
Limitations
- The 30% rule uses gross income (before tax); some renters prefer to base affordability on take-home to build in room for savings and irregular expenses.
- Does not model utilities, renter insurance, parking, or amenity fees — plan for $150-$400/mo in these depending on city and building.
- Does not adjust for student loan payments, car payments, or other fixed monthly debt that reduces true rental capacity.
The 30% rule is a rule of thumb, not a lending decision. Landlord income verification standards may differ. This calculator does not provide financial advice.