🎲 An independent personal project, not affiliated with any official source — for fun, not financial advice. Don't trust these numbers; do your own research before any real decision. Terms →

Suffolk County Home Cost Calculator

Verified 2025-26 tax rates from official town rate sheets
Autosaved

Can we afford this house?

Answer five quick questions — no forms, no jargon — and see the real monthly cost.

Property

Financing

15.0%
3.5%20%35%
6.88%
4%7%10%

Your Finances

Income, cash, rate and term are shared across every tab on this site — change them here and they update everywhere, including Basic.

If Rates Move

PITI at your current price and down payment.
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monthly

Monthly Cost

Principal & interest—
Property taxes—
Insurance—
Mortgage insurance—
HOA—
PITI (lender's number)—
+ maintenance—
+ utilities—
True monthly cost—

Affordability

Housing ratio (PITI ÷ income) — target ≤28%—
Full DTI (PITI + debts) — target ≤36%—
True cost ÷ income—

Loan, Cash & Lifetime Cost

Down payment—
Base loan—
+ FHA upfront MIP (1.75%)—
Total loan—
Estimated closing costs—
Cash needed at closing—
Left over—
Total interest over loan life—
Total paid (P&I only)—
Closing cost breakdown — click any amount to edit

Equity & Balance Over Time

Save This Property

My Properties

Compare Properties

Add a Source

Add a Gift

Gifts from family are allowed on FHA and most conventional loans, but lenders require a signed gift letter and proof of transfer. Track them separately — a gift that hasn't been promised in writing isn't cash you can count on.
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total cash available

Where It's Coming From

Gifts

What This Covers

Inputs

28% is the conventional guideline. 25% comfortable, 33% a stretch.
These four are shared with Basic/Advanced — edit in either place. Target town is set here only.
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maximum purchase price

How We Got There

Cash available—
− closing costs—
− emergency fund—
Available for down payment—
Max monthly PITI at target—
Down payment %—

At Other Thresholds

Refinance Scenario

Starts from the loan on your Calculator tab.
3 yrs
1 yr8 yrs15 yrs
5.50%
3%6%9%
Typically 2–5% of the loan.
3.0%/yr
0%4%8%
Drives equity, which decides whether mortgage insurance can come off.
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monthly change

At Refinance Time

Remaining balance—
Estimated home value—
Equity—
Loan-to-value (LTV)—
New loan amount—

Payment Comparison

Is It Worth It?

Monthly saving—
Break-even—
Interest still owed — keep current loan—
Interest still owed — after refinancing—
Lifetime interest difference—
Years left — current—
Years left — refinanced—

Points & Credits

Starts from the loan on your Calculator tab. Positive points buy the rate down (paid upfront); negative points are a lender credit — you take a higher rate in exchange for cash toward closing.
0.000
−4 (credit)0+4 (buy down)
Lender-set, typically 0.125%–0.375% per point. Ask your lender for their exact number — this is a placeholder.
7 yrs
1 yr15 yrs30 yrs
Median U.S. homeownership before selling or refinancing is roughly 7–10 years — the break-even below only pays off if you keep the loan at least that long.
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at closing

Rate & Payment

Rate on your Calculator tab—
Rate with this many points—
Principal & interest — no points—
Principal & interest — with points—
Monthly change—

Is It Worth It?

Cost (or credit) at closing—
Cash needed at closing, adjusted—
Break-even—
Total cost over your time horizon—

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Town & District Directory

Click a name for the full profile, click any column header to sort, and use “Choose columns” to add or remove metrics.
Tick up to 5 towns or districts to compare them side by side, then open the Compare tab.

Towns

Choose columns & sort

School Districts

Choose columns & sort

Data Sources

Every dataset this site uses, with a live link and the date it was last checked against the primary source. Numbers move — property tax rates and home prices in particular update at least annually, sometimes faster.

Current Pricing — Town by Town

This site doesn't republish sale-price figures from real estate listing sites — every town's home value shown elsewhere on this site is Census ACS 2019-23, which runs well below current asking prices. Use the live links below to check current Redfin listings yourself.

Compare Towns

Growth Assumptions

P&I is fixed. Everything else compounds — which is why the payment you sign for is not the payment you live with.
NY caps school levy growth near 2%, but assessments and special districts move too. 2–3% is a reasonable planning range.
Coastal Long Island has run well above general inflation.

Pay It Down Faster

Biweekly adds one extra monthly payment a year.

Rent Instead?

Broker commission, transfer tax and attorney on the way out.
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cost in year 10

What It Costs, Year by Year

Rent vs Buy

Points & Buydown

1 point = 1% of the loan, paid at closing.
Typically 0.25%, but ask your lender — it varies.

Same House, Different Loans

Your current price, down payment and rate, run through four structures. The 15-year uses the same rate — in practice it usually prices lower, so ask for a real quote.

Property Tax Rates — Official Town Rate Sheets 2025-26

Two units, same thing. Rates are published as dollars per $1,000 of value, which is the standard way New York towns express them. The effective percentage is simply that number divided by 10.
4.57 per $1,000  =  0.46%  =  $2,744/yr on a $600,000 home
22.89 per $1,000  =  2.29%  =  $13,732/yr on a $600,000 home
Annual tax = rate × (price ÷ 1,000). Brookhaven publishes per $100 of assessed value; converted here at a 0.5139% residential assessment ratio so every town is directly comparable.
You can edit any rate. Enter your figure in the “Your rate” column in dollars per $1,000 — the percentage updates beneath it so you can check yourself. From a real tax bill: annual tax ÷ market value × 1,000. A $14,000 bill on a $620,000 home is 14000 ÷ 620000 × 1000 = 22.58. Edits are highlighted, saved with your file, and used everywhere. Click ↺ to restore. Click a town name to load it into the calculator.

About This Tool

What it does

Estimates the true monthly cost, cash requirement and lifetime interest of buying a home in Suffolk or Nassau County — using a county selector, and property tax rates computed from official town-level or state data rather than a single flat county average.

Where the tax rates come from

Suffolk (Brookhaven, Southampton and Riverhead towns): Town of Brookhaven 2025-2026 Taxable Districts Rate Sheet and Town of Southampton 2025-2026 Tax Rate Sheet (both checked 2026-08-05 — see the full ). Each rate is the sum of that location's published line items: school, library, county, town, fire, ambulance, lighting, water and park districts. Brookhaven publishes per $100 of assessed value, Southampton per $1,000 of full market value; both are converted to a single full-market basis using a 0.5139% Brookhaven residential assessment ratio derived from five districts.

Nassau (all five towns/cities): NYS Dept. of Taxation and Finance's Property Tax Rates dataset (checked 2026-08-11), which NYS already publishes on a full-market-value basis — no assessment-ratio conversion needed. Each rate is County + Town + School only; special districts (fire, water, garbage, library) are not included, matching Suffolk's own scope. Nassau's tax bill is structurally different from Suffolk's: assessment is centralized at the county (not per-town), and school tax is billed completely separately from the "general tax" (county + town + special districts) — this tool models the combined effective rate either way.

Closing costs — what is and isn't included

Included: origination, appraisal, title insurance, recording fees, NY mortgage recording tax, attorney, prepaid taxes and insurance, inspection, survey. Every line is editable.

NY mansion tax of 1% applies to residential purchases at $1,000,000 and above and is included automatically above that threshold.

Peconic Bay Community Preservation Fund transfer tax applies on the East End — Southampton, East Hampton, Riverhead, Shelter Island and Southold — and is paid by the buyer. It is included for locations in those towns, with an editable rate and exemption because both have changed over time and vary by town and whether the parcel is improved. Verify the current rate and exemption with your attorney.

Not included: the New York State real estate transfer tax, which is customarily paid by the seller. Lender credits, seller concessions and rate buydowns are also not modeled.

How FHA is modeled

Upfront MIP of 1.75% is added to the loan balance because it is financed rather than paid at closing. Annual MIP is 0.45% of the loan at 10% or more down, otherwise 0.55%. At 10%+ down FHA MIP runs 11 years; below that it lasts the life of the loan. Conventional PMI is modeled at 0.5% annually and disappears at 20% down.

How the refinance tab works

It amortizes your loan forward to the refinance date, grows the home value at your chosen appreciation rate, and computes the resulting loan-to-value. That LTV decides whether mortgage insurance can be removed — which for FHA generally requires refinancing into a conventional loan, since FHA MIP cannot be cancelled by equity alone at under 10% down.

The lifetime interest comparison is what most refinance calculators omit. Dropping into a new 30-year term restarts the clock, so a lower monthly payment can still mean more interest overall. Both figures are shown. Future rates are unknowable — treat this as scenario testing, not a forecast.

Other limitations

  • Village taxes are excluded. Every incorporated village in either county — Southampton, Quogue, Westhampton Beach, Port Jefferson and Shoreham in Suffolk, and dozens more in Nassau — levies an additional village tax on top of the town rate. Flagged per location in the Rates tab.
  • Riverhead town rows are aggregator-derived — no official Riverhead rate sheet was obtained.
  • Exemptions excluded. STAR, veterans and senior exemptions all reduce actual bills.
  • District-level rates. A parcel's real bill depends on its own assessed value and special districts. Override the rate when you have the actual bill.
  • Split hamlets. Eastport spans two towns ($3,000/yr difference on a $700k home); Manorville spans two school districts ($4,700/yr).
  • Assessment ratios change annually.

Not financial advice

This is arithmetic on the assumptions you enter. Whether FHA or conventional is right for you depends on credit, reserves, seller preferences and loan limits this tool does not model, and the county's FHA loan limit is not checked. Take these numbers to a licensed mortgage broker and a real estate attorney.

Your data

Everything stays in your browser — nothing is uploaded. Work auto-saves to local storage, and the Save button downloads a JSON file containing your inputs, saved properties with their listing links, and any custom tax rates.

Cookies & third-party embeds

This site does not set any cookies of its own. The inputs, saved properties, and custom tax rates described above live in your browser's local storage — not a cookie, and never sent to any server. The one exception is the "Buy Me a Coffee" button in the corner, a third-party widget loaded from buymeacoffee.com; it runs its own script and may set its own cookies or use its own tracking, which this site has no control over. Nothing else on the page depends on it — a browser extension that blocks third-party scripts, or simply not clicking it, removes it entirely.

Terms of use

This is an independent personal side project, built by one person for their own house search. It is not a company, not a product, and not affiliated with, endorsed by, sponsored by, or verified by any town, county, state agency, school district, real estate brokerage, MLS, lender, or financial institution. Nothing on this site is official, and nothing here should be assumed accurate just because it cites a government or public source — the citation tells you where a number originally came from, not that it has been checked recently or compiled correctly.

This calculator is for entertainment purposes only and is not financial, legal, or tax advice — do not use it to make any real estate, financing, or purchasing decision. Do not trust the numbers on this site. Do your own independent research and verify everything that matters — every tax rate, every demographic figure, every school statistic, every price — directly with the primary source (your town's receiver of taxes, a licensed mortgage broker, a real estate attorney) before relying on any of it for anything real. By using this site you agree to indemnify and hold harmless the site owner from any claims, losses, or damages arising from your use of it.

Demographic, school, tax-rate, and price data on this site comes from third-party public sources — see the Sources tab for what's cited where. This data may be outdated, incomplete, or inaccurate, may contain errors introduced while compiling it, and none of it is verified in real time — confirm anything that matters against the primary source before relying on it. This site links to third-party sites (including town tax offices, school data portals, and real estate listing services) for reference and does not control, endorse, or vouch for their content.

Your plan

Until you sell or refinance. The longer you keep it, the more a higher rate costs you.

Your loan

Your lock

Cannot be negative

If the lock expires

Ask your lender for their relock rules and fee. These change the answer more than anything else here.
Table & chart ranges
Days: min ≥ 1, max ≤ 3650, min < max
Holding: min ≥ 1, max ≤ 40, min < max

Refinance

Years must be 0-40 and inside your holding period Must be between 0 and 20
Title insurance is a filed rate, not a quote: Suffolk is TIRSA Zone 2, and a refinance within ten years of your purchase pays 70% of the standard rate, less the discount above. Zone 2 rates include the title search and one tax lot's tax search.
Under NY Tax Law 255 a consolidated mortgage is taxed only on new money, so a rate-and-term refinance pays no mortgage recording tax. Your current lender has to agree to assign the mortgage.
Cannot be negative Cannot be negative
where that number comes from
Only the recording fees and the mortgage recording tax come from published schedules. The rest are estimates: replace them with the figures on your lender's Loan Estimate.
Start rates: min ≥ 0, min < max
Target rates: min ≥ 0, min < max

Breakeven rate by extension length

Each line is one holding period. Above the line, extending was worth it.

Breakeven matrix

Each cell is the market rate at which extending that many days breaks even against holding the loan that long. If you believe the market rate at closing would be above the cell, extending is the cheaper choice. Closing dates that fall on a weekend or a federal holiday are shown in amber. The highlighted column is how long you plan to keep the loan.