Suffolk County Home Cost Calculator

Tell us about the property

Income, cash, rate, town and loan term are shared across every tab on this site — change them here (or in Advanced) and they update everywhere. Loan type, interest rate, term, and monthly costs use typical defaults here. Switch to to fine-tune everything.

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monthly

Monthly Cost

PITI (lender's number)—

+ maintenance & utilities—

True monthly cost—

Affordability

Housing ratio — target ≤28%—

Cash needed at closing—

Left over after closing—

Save This Property

Property

Purchase price

Location

Village tax, $ per $1,000 (if incorporated)

Address (optional) Listing link (optional)

Financing

Loan type

Down payment15.0%

3.5%20%35%

Down payment dollars

Interest rate6.88%

4%7%10%

Interest rate percent Term (years)

Your Finances

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

Household income (annual)

Cash available (total)

Other monthly debts

Insurance /mo

Maintenance /mo

Utilities /mo

HOA /mo

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

Notes Rating

My Properties

Side by Side

Add a Source

What is it Amount you'd put toward the purchase Type Status

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.

From Amount How firm is it Relationship (lenders ask)

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total cash available

Where It's Coming From

Gifts

What This Covers

Inputs

Target housing ratio (%)

28% is the conventional guideline. 25% comfortable, 33% a stretch.

Emergency fund to keep Target town (independent of Basic/Advanced)

These four are shared with Basic/Advanced — edit in either place. Target town is set here only.

Household income Cash available

Rate (%)

Term

Loan type

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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.

Refinance in3 yrs

1 yr8 yrs15 yrs

New interest rate5.50%

3%6%9%

New term New loan type Refinance closing costs

Typically 2–5% of the loan.

Roll costs into the new loan

Home appreciation3.0%/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—

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Town & District Directory

Filter

156 places and 67 school districts. 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

Compare

Growth Assumptions

P&I is fixed. Everything else compounds — which is why the payment you sign for is not the payment you live with.

Property tax growth /yr

NY caps school levy growth near 2%, but assessments and special districts move too. 2–3% is a reasonable planning range.

Insurance growth /yr

Coastal Long Island has run well above general inflation.

Utilities & maintenance growth /yr Your income growth /yr Home appreciation /yr

Pay It Down Faster

Extra principal /month Biweekly payments (26 half-payments a year)

Biweekly adds one extra monthly payment a year.

Rent Instead?

Your rent today /month Rent growth /yr Return on invested cash /yr Cost to sell (%)

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

Discount points

1 point = 1% of the loan, paid at closing.

Rate cut per point

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

Filter rates

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.

57 per $1,000  =  0.46%  =  $2,744/yr on a $600,000 home

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 the Suffolk County towns of Brookhaven, Southampton and Riverhead — using property tax rates computed from official town rate sheets rather than county averages.

Where the tax rates come from

Town of Brookhaven 2025-2026 Taxable Districts Rate Sheet and Town of Southampton 2025-2026 Tax Rate Sheet. 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.

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. Southampton, Quogue, Westhampton Beach, Port Jefferson and Shoreham are incorporated villages levying an additional village tax on top of the town rate.
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 Suffolk 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.

Terms of use

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. 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.