To calculate Nassau County property tax, multiply your property’s taxable assessed value by each applicable tax rate per $100, divide by 100, and add the totals from every taxing jurisdiction that bills your parcel. You need three things to do the math: your assessed value, any exemptions that reduce it, and the current rates set by your school district, county, town, and special districts. Everything else is bookkeeping.
The Formula
For each line item on your bill, the arithmetic is identical:
Tax for one jurisdiction = (Taxable Assessed Value × Tax Rate per $100) ÷ 100
Run that calculation for every jurisdiction that taxes your property, then add the results. The total is your annual property tax. The complication in Nassau County is not the formula; it is that a single parcel is usually taxed by five or more separate authorities, each with its own rate.
Find Your Assessed Value
Your starting number comes from the Notice of Tentative Assessment that the Nassau County Department of Assessment mails each January when it publishes the tentative assessment roll. The notice shows your property’s estimated fair market value, the Level of Assessment the county applied, and the resulting assessed value. If you cannot find the notice, pull the figures from the county’s Land Records Viewer at lrv.nassaucountyny.gov using your address or parcel number.
The assessed value is what the county gets when it multiplies market value by the Level of Assessment, a ratio of assessed values to market values in the jurisdiction.1New York State Department of Taxation and Finance. The Locally Stated Level of Assessment For Class 1 residential property in Nassau County, the LOA has historically been very low, which is why a home worth several hundred thousand dollars may carry an assessed value of only a few hundred or a few thousand dollars. You do not need to run this calculation yourself; both figures appear on the notice. But knowing the relationship explains why the per-$100 rates on your bill look so large: they are being applied to a small base.
Your property class also matters, because each class has its own Level of Assessment and carries a different share of the overall levy. Nassau County sorts all real property into four classes under New York Real Property Tax Law Section 1802: Class 1 for one-, two-, and three-family homes (including separately assessed owner-occupied mobile homes); Class 2 for other residential property such as cooperatives, condominiums, and apartment buildings; Class 3 for utility company property; and Class 4 for everything else, mostly commercial and industrial.2New York State Senate. New York Real Property Tax Law RPT 1802
Subtract Any Exemptions
Before rates are applied, eligible homeowners can reduce the assessed value through exemptions. The reduced figure is your taxable assessed value, and that is the actual base for the calculation. Skip this step and you will overstate your tax every time.
STAR
The School Tax Relief program reduces school taxes for owner-occupied primary residences. Basic STAR is available to homeowners with combined income of $500,000 or less for the credit, or $250,000 or less for the exemption. Enhanced STAR provides a larger reduction for homeowners aged 65 and older with income of $110,750 or less for the 2026–2027 school year.3New York State Department of Taxation and Finance. Types of STAR Homeowners who bought after 2015 generally receive STAR as a check or direct credit rather than as a reduction on the assessment, but the financial effect is the same.
Veterans
Three veterans exemptions are available, each reducing assessed value by a different method:
- The Alternate Veterans Exemption reduces assessed value by 15% for qualifying veterans, with an additional 10% for combat-zone service and further relief proportional to a service-connected disability rating.
- The Eligible Funds Exemption reduces assessed value by the amount of eligible funds, such as VA benefits, used to purchase the home.
- The Cold War Veterans Exemption provides a 15% reduction (subject to a cap) for veterans who served between September 2, 1945, and December 26, 1991, with additional disability-related relief.
The property must be owned by the veteran, their spouse, or an unremarried surviving spouse.
Senior Citizens
Homeowners aged 65 and older may qualify for an exemption that reduces taxable assessed value by up to 50%. Each municipality and school district sets its own income threshold, which can range from $3,000 to $50,000. Some jurisdictions also use a sliding scale that provides smaller reductions of 5% to 20% for seniors whose income exceeds the local cap but stays below $58,400.4New York State Department of Taxation and Finance. Senior Citizens Exemption Confirm the number with your town assessor’s office.
Most Nassau County exemption applications are due in the first few months of the year, often by March 1 or March 15. Exemptions are not applied retroactively, so a missed deadline means paying the full amount for the entire year.
Gather Every Tax Rate That Applies
Your bill is not one tax; it is a stack of taxes imposed by jurisdictions that happen to overlap at your address. A typical Nassau County bill includes:
- School district, usually the largest single piece.
- County government, funding countywide services such as police, courts, and social services.
- Town government (Hempstead, North Hempstead, or Oyster Bay) or city (Glen Cove or Long Beach).
- Village taxes, if the property sits in an incorporated village. Town rates are typically lower in that case, offsetting some of the village charge.
- Special districts for fire, library, sanitation, water, and parks, each appearing as a separate line item.
Roughly 64% of a typical bill goes to the school district, about 14% to the county, and the remaining 22% is split among the town, villages, and special districts.5Nassau County. Understanding Your Property Taxes The exact mix depends on where you live and which districts serve the parcel.
Every rate is quoted in dollars per $100 of assessed value. Current rates appear on your tax bill, through the town receiver of taxes, and on the Land Records Viewer, which lists individual rates by parcel. Each jurisdiction sets a new rate every year based on its budget, so last year’s numbers will not give you an accurate estimate for this year.
Run the Numbers
Suppose your home has a market value of $600,000 and the county’s Level of Assessment produces an assessed value of $600. After a $100 exemption, your taxable assessed value is $500. If the school district rate is 900.00 per $100 of assessed value and the combined general rate for the county, town, and special districts comes to 500.00 per $100, the math works out this way:
- School tax: ($500 × 900.00) ÷ 100 = $4,500
- General tax: ($500 × 500.00) ÷ 100 = $2,500
- Total annual tax: $4,500 + $2,500 = $7,000
The rates above are hypothetical. A real Nassau County bill will have many more line items, with individual entries for the county, town, fire district, library district, sanitation district, and so on. Run the same formula for each one, then total them. The per-$100 rates look enormous compared with other counties, but that is a consequence of the low Level of Assessment, not of the dollar amount you actually owe.
If Your Number Looks Too High
Tax rates are set by elected bodies and school board budgets, so the rates themselves are not open to challenge from an individual homeowner. The piece you can contest is the market value the Department of Assessment assigned to your property, by filing a grievance with the Nassau County Assessment Review Commission, an independent tribunal separate from the Department of Assessment.6New York State Senate. Challenging Your Nassau County Property Assessment The filing window opens when the tentative roll is published on January 2 and typically runs through early March, though the deadline has been extended to March 31, 2026 for the current cycle.7Nassau County. Nassau County Assessment Review Commission A reduction in assessed value lowers every line item on the bill at once, because every jurisdiction uses the same base figure.