New Jersey's real property tax is an ad valorem tax, or a tax according to value. The standard measure of property value is true value or market value, that is, what a willing, knowledgeable buyer would pay a willing, knowledgeable seller on the open market at a bona fide sale as of the statutory October 1 pretax year assessment date.
County, municipal and school budget costs determine the amount of property tax to be collected. A town's general tax rate is calculated by dividing the total dollar amount it needs to raise, by school, county, municipality, etc, by the total assessed value of all its taxable property. An individual's property taxes are then calculated by multiplying that general tax rate by the assessed value of his particular property.
The tax rate for Roxbury is the total of the rates for the school, county, county open space, municipal and municipal open space. It is not just the municipal expenses that affect your property taxes.
Your tax bill itemizes how much of your property taxes go to the various taxing agencies.