NYC Affordability

Why this exists

Most rent-affordability and mortgage calculators are built around generic national assumptions: a flat debt-to-income ceiling, a simple down payment percentage, maybe a property tax estimate. NYC housing doesn't work that way. A co-op board can require 12–24 months of post-closing reserves on top of the down payment. A condo purchase over $1,000,000 crosses a mansion tax cliff that adds tens of thousands of dollars at a single dollar boundary. Renters are protected, and priced, differently since the FARE Act changed who pays broker fees. Affordable housing eligibility runs on HUD's Area Median Income bands, not a simple income cutoff.

We built a set of tools that model these mechanics directly, so the numbers reflect how a co-op board, a condo lender, a landlord, or HPD's Housing Connect lottery actually evaluates an applicant, not a generic estimate.

What's here

13 free calculators, all running entirely in your browser:

And the reading behind them, each citing dated sources:

• 32 guides on renting, buying, co-ops, taxes, and affordable housing in New York City
• 45 glossary terms, from the 40x rule to the mortgage recording tax
• 10 neighborhood pages with cited market figures, plus borough hubs
• Data downloads of every cited figure and default assumption, in JSON and CSV

The site is maintained continuously: defaults are re-checked against their sources on a schedule, and every change that could move a number is logged on the changelog, with mistakes listed on the corrections page.

Methodology & sourcing

Every default value in these calculators (mortgage rates, board DTI limits, reserve requirements, closing cost percentages, median rents, AMI income limits) is either taken from a named source or labeled as our own illustrative estimate, so you know which numbers to replace with your own. The sources used across the site include:

• Freddie Mac Primary Mortgage Market Survey (PMMS): current conventional mortgage rates
• NYC Department of Finance / ACRIS: mortgage recording tax, transfer tax, and real property records
• New York State Department of Taxation and Finance: mansion tax tiers
• HUD Income Limits: Area Median Income (AMI) figures used for affordable housing eligibility
• NYC Housing Preservation & Development (HPD): affordable rent methodology and Housing Connect band structure
• StreetEasy Market Reports: median asking rent used as a default reference point
• NYC Department of Consumer and Worker Protection (DCWP): FARE Act broker-fee guidance
• New York State Attorney General: tenant rights and security deposit law

Every calculator links its individual sources inline in its own "How this works" section, and each default is editable; the sourced value is a starting point, not a constraint. Defaults are updated by hand when a source publishes new figures (rates, tax tiers, income limits). The sources & data status page lists every default with what kind of number it is and the date it was last re-verified, or says so when no check has been recorded yet. See the methodology for how the math works.

How the math works, at a high level

Every calculator on this site (rent, co-op, and condo) reduces the same question to two competing constraints, then takes whichever one is lower:

1. Cash / reserves: what your liquid assets can actually cover: move-in costs and a security deposit for rent, or a down payment plus closing costs plus a post-close reserve cushion for a purchase.
2. DTI / income: what a landlord, co-op board, or mortgage lender will approve based on your monthly housing cost relative to your gross income.

Whichever constraint produces the lower number is your real ceiling; you can't spend more than either allows. The comparison dashboard shows this "binding constraint" side by side across all three housing types, since which one binds (and by how much) varies a lot between renting, buying a co-op, and buying a condo.

Who maintains this

View the source on GitHub →
Found an error, an outdated rate, or have a feature request? See the Contact page for the fastest way to reach the maintainer. Past mistakes and how they were fixed are on the corrections page.

Disclaimer

These calculators are for informational purposes only and do not constitute financial, legal, or mortgage advice. Tax rates, board requirements, lender guidelines, and closing costs vary by building, lender, and transaction, and change over time. Always verify figures with a licensed mortgage professional and a real estate attorney before making a housing decision. See the privacy policy for how your data (and it stays only in your browser) is handled, and the terms of service for the full legal terms of using this site.