What this calculator does
This calculator estimates how much rent you can comfortably afford in San Francisco by running three tests at once: the familiar 30% of gross income guideline, the income test landlords in San Francisco commonly use (monthly income of at least three times the rent), and a debt-to-income limit that includes your other payments. The lowest of the three is shown as your comfortable rent, next to your estimated take-home pay after San Francisco taxes.
San Francisco has some of the highest rents and home prices in the country, with a large share of housing in older buildings covered by the city's rent ordinance. Neighborhoods range from the Mission and SoMa to the Sunset, Richmond and Bernal Heights, and fog belt western neighborhoods often cost less than central ones.
How to use it
- Enter gross yearly income for everyone on the lease.
- Add monthly debt payments such as car and student loans.
- Adjust the share of income for rent if you prefer a stricter or looser budget than 30%.
- Set the security deposit and any broker or application fees you expect to pay.
- Compare the result with listings in the neighborhoods you are considering.
The formula
Comfortable rent = the lowest of (1) gross monthly income × your chosen share, (2) the landlord income test (annual income ÷ 36), and (3) 43% of gross monthly income minus existing debt payments. Move-in cash = first month + deposit + fees.
Worked example for San Francisco
Household income $125,000, $300 of monthly debt payments, 30% target:
| Check | Monthly amount |
|---|---|
| Gross monthly income | $10,417 |
| Estimated take-home per month | $7,308 |
| Existing debt payments | -$300 |
| 30% of gross rule | $3,125 |
| Landlord rule: 3x the monthly rent in monthly income (common screening rule) | $3,472 |
| Rent that keeps total debt at 43% of gross | $4,179 |
| Rent that passes all tests | $3,125 |
Leaves about $3,883 a month after rent and debt payments from $7,308 take-home pay.
What affects rent affordability in San Francisco
For comparison, Rate and Reason's rough starting estimate for a typical one-bedroom in San Francisco is $3,300 a month and $4,600 for a two-bedroom, though neighborhoods such as the Mission, SoMa, Noe Valley, the Sunset, the Richmond, Bernal Heights, the Marina and the Excelsior vary widely. California caps most security deposits at one month's rent since July 2024.
San Francisco residents pay California income tax, which runs from 1% to 12.3% plus a 1% Mental Health Services Tax on income above $1 million. There is no separate San Francisco personal income tax; the city's own taxes fall on businesses through gross receipts and payroll-based measures.
Common mistakes and tips
- Using take-home pay with a gross-income rule — the 30% guideline is based on gross pay.
- Ignoring utilities, renters insurance and commuting, which can add hundreds a month.
- Forgetting that roommates' income usually counts toward a landlord's income test only if they are on the lease.
- Budgeting for the 1-month deposit and first month's rent before you apply.
- Remembering rent rises at renewal — leave room in the budget for an increase.
Frequently asked questions
How much rent can I afford in San Francisco on $125,000?
This calculator's comfortable rent for that income, with $300 of debt payments, is $3,125 a month based on the strictest of three common tests.
Is the 30% rule realistic in expensive cities?
It is a guideline, not a law. Many renters in high-cost cities spend more, but the higher the share, the less room there is for savings and surprises.
What do San Francisco landlords usually require?
Many landlords look for monthly income of about three times the rent, a credit check and proof of income such as pay stubs or an offer letter.
How much is a security deposit in San Francisco?
One month's rent for most rentals, under California's limit that took effect July 1, 2024. San Francisco also requires landlords to pay yearly interest on deposits at a rate set by the Rent Board.
Sources
Disclaimer
This calculator provides estimates for educational purposes only and is not financial, tax, legal, real estate, or insurance advice. Consult a licensed professional before making decisions.