What is the difference between the equalization rate and the residential assessment ratio (RAR) in New York?

Both numbers express assessments as a percentage of market value, but they serve different purposes — and for a homeowner grievance, the RAR is the one you usually cite.

Equalization rate. The state's equalization rate is the ratio of a municipality's total assessed value to its total market value. A rate of 100 means the town assesses at 100% of market value; a rate of 50 means it assesses at roughly half. Its main job is to fairly apportion taxes and aid across taxing jurisdictions — it is not designed to correct an individual unfair assessment.

Residential assessment ratio (RAR). The RAR is the same idea but limited to residential property: the ratio of aggregate residential assessments to aggregate residential full (market) value. It tells you the typical level at which homes like yours are assessed in that city or town.

Why the RAR wins your grievance. New York lets you grieve an unequal assessment — being assessed at a higher percentage of market value than other homes. To prove it, take your home's estimated market value and multiply by the RAR. If your actual assessed value exceeds that figure, you are over-assessed relative to your neighbors. Example: market value $400,000 and a RAR of 2.5% imply an equitable assessment of $10,000; if you are assessed at $13,000, you have an unequal-assessment claim.

Where to find both. The state publishes equalization rates and RARs by county and municipality. Form RP-524 Part Four explicitly allows you to support an unequal claim with the RAR.

Use the RAR for the individual math on your home; mention the equalization rate only if you are challenging the town-wide level of assessment.