40x Rent Calculator
Enter the rent and your yearly income to see whether you meet the 40x rule, how much you'd need, and what a guarantor would need. Or work out the most rent your income qualifies for.
By Tess Mullins · Updated
Your numbers
Income needed at 40x
$100,000 a year
Your $90,000 is $10,000 short.
- That's $8,333.33 a month before taxes, so the rent is 30% of it.
- At your income, the rule allows up to $2,250 a month.
- A guarantor at 80x would need $200,000 a year.
The 40x rule is a landlord custom, not a law, and each landlord sets its own. How we calculate
General information, not legal or financial advice.
The short answer
Under the 40x rule, your yearly income before taxes should be at least 40 times the monthly rent. A $2,500 apartment needs $100,000 a year. To go the other way, divide your yearly income by 40: $75,000 a year qualifies for up to $1,875 a month.
The rule is a landlord custom, not a law. It’s common in New York City, and some landlords ask for 40 to 50 times the rent. Outside New York, most landlords put the same idea in monthly terms: gross monthly income of about 3x the rent, which is 36x a year. The calculator lets you change the multiple to match the one you’re given: enter 36 for the 3x rule.
How to use the calculator
- Pick what you want to know: the income needed for a rent, or the most rent for an income.
- Enter the monthly rent of the apartment you’re looking at.
- Enter your yearly income before taxes. Applying with someone else? Ask the landlord whether they add incomes together before you enter a combined number.
- Check the multiple. 40x is the default. If the listing or the broker gives a different number, change it.
- Check the guarantor rule if you might need one. Guarantors are often asked for 80 to 100 times the rent.
Use Copy link to save the result or send it to a roommate or a guarantor.
Income needed for common rents
The yearly income landlords ask for at common monthly rents, at 40x, at the stricter 50x and for a guarantor at 80x:
| Monthly rent | Income at 40x | Income at 50x | Guarantor at 80x |
|---|---|---|---|
| $1,500 | $60,000 | $75,000 | $120,000 |
| $2,000 | $80,000 | $100,000 | $160,000 |
| $2,500 | $100,000 | $125,000 | $200,000 |
| $3,000 | $120,000 | $150,000 | $240,000 |
| $3,500 | $140,000 | $175,000 | $280,000 |
| $4,000 | $160,000 | $200,000 | $320,000 |
How we calculate
- Income needed = monthly rent × the multiple (40x by default).
- Max rent = yearly income ÷ the multiple.
- Guarantor income = monthly rent × the guarantor multiple (80x by default).
- Share of income: a year has 12 months, so at exactly 40x the rent is 12 ÷ 40 = 30% of your gross monthly income.
The defaults come from Columbia University’s rental guide, which says landlords usually ask for total gross annual income of 40 to 50 times the monthly rent, and 80 to 100 times the rent from a guarantor. Elsewhere in the US the common screening rule is 3x the rent in gross monthly income (TransUnion SmartMove’s guide for landlords), which is 36x a year and puts rent at 33.3% of gross income. For comparison, NYC’s Housing Connect guide calls housing affordable when a household spends no more than about one-third of its income on rent.
Worked examples
Example: Checking an income against 40x
What we know
- Rent: $2,500 a month
- Yearly income: $90,000 before taxes
- Rules: 40x for the tenant, 80x for a guarantor
How it works out
- Income needed: $2,500 × 40 = $100,000 a year.
- $90,000 is $10,000 short.
- A guarantor at 80x: $2,500 × 80 = $200,000 a year.
$100,000 a year is needed; a guarantor would need $200,000.
Example: The most rent for an income
What we know
- Yearly income: $75,000 before taxes
- Rule: 40x the rent
How it works out
- Max rent: $75,000 ÷ 40 = $1,875 a month.
- Check: $1,875 × 40 = $75,000.
- That rent is 30% of the gross monthly income ($6,250).
Up to $1,875 a month.
Example: What a guarantor needs
What we know
- Rent: $3,200 a month
- Yearly income: $60,000 before taxes
- Rules: 40x for the tenant, 80x for a guarantor
How it works out
- Income needed: $3,200 × 40 = $128,000 a year.
- $60,000 is $68,000 short.
- A guarantor at 80x: $3,200 × 80 = $256,000 a year.
$128,000 a year is needed; a guarantor would need $256,000.
If you don’t meet the rule
- Look at rent within your range. The calculator’s max-rent mode shows the most rent your income qualifies for under the landlord’s multiple, and the rent affordability calculator checks it against HUD’s 30% line, after utilities.
- Ask about a guarantor. Check the guarantor multiple first. At 80x, a $2,500 apartment needs a guarantor earning $200,000 a year.
- Ask what else the landlord accepts. Requirements differ from landlord to landlord, so ask before you pay an application fee.
- Budget for the bills too. The rule only looks at rent. The apartment utilities cost calculator estimates what electricity and gas add each month in your state.
- Weighing a purchase instead? The rent vs buy calculator follows renting and buying year by year at today’s mortgage rate and shows when buying would pull ahead.
- Know the deposit limit in New York. New York law (General Obligations Law 7-108) says a deposit or advance can’t be more than one month’s rent.
New York City rules worth knowing
- Housing vouchers: when a voucher sets your share of the rent based on your income, the NYC Commission on Human Rights says landlords can’t add income requirements, and may not require guarantors or co-signers.
- Application fees: New York caps application, background check and credit check fees at $20 or the actual cost, whichever is less.
- Broker fees: since Jun 11, 2025, the FARE Act stops landlords from passing their own broker’s fee on to tenants and requires them to disclose the fees you’ll pay.
Have your documents ready before you apply. Columbia University’s rental guide lists a letter from your employer, your last two pay stubs, your last two years of tax returns, your last two months of bank statements and your previous landlords’ contact details. A guarantor provides the same.
These are general rules and guidance, not legal or financial advice. Landlords set their own requirements, and local law can add protections.
Frequently asked questions
What does 40x rent mean?
It means a landlord wants your yearly income to be at least 40 times the monthly rent. For a $2,500 apartment, that's $100,000 a year. It's a landlord custom, not a law, and some landlords ask for 40 to 50 times the rent.
Is 40x rent based on gross or net income?
Usually gross income, before taxes. Columbia University's rental guide describes the requirement as total gross annual income. Each landlord sets its own rules, so ask what counts if you're not sure.
How much rent can I afford with the 40x rule?
Divide your yearly income before taxes by 40. With $75,000 a year, that's up to $1,875 a month. At exactly 40x, the rent is 30% of your gross monthly income.
How much does a guarantor need to earn?
Guarantors are often asked to earn 80 to 100 times the monthly rent, according to Columbia University's rental guide. At 80x, a $2,500 apartment needs a guarantor who earns $200,000 a year.
Is the 40x rule a law?
No. No law or government agency sets it. Landlords choose their own income requirements, and the calculator lets you change the multiple to match the one you're given.
What if my landlord asks for 3 times the rent instead?
That's the same idea in monthly terms, and it's what most landlords outside New York City use: gross monthly income of at least 3x the rent, which works out to 36x the rent a year. Enter 36 as the multiple. It's a little easier to meet than 40x: at 36x, rent is 33.3% of your gross income instead of 30%.
Can a landlord use 40x for a tenant with a housing voucher in NYC?
Not when the voucher sets your share of the rent based on your income. The NYC Commission on Human Rights says adding income requirements in that case violates the city's Human Rights Law, and that landlords may not require guarantors or co-signers.
Do roommates' incomes count together?
That's up to the landlord. Some add incomes together and some look at each person separately, so ask before you apply and before you pay any fee.
How much can a New York landlord charge to apply?
New York caps application, background check and credit check fees at $20 or the actual cost, whichever is less. In New York City, the FARE Act also stops landlords from passing their own broker's fee on to tenants, since Jun 11, 2025.
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