Common level range
The Chapter 123 corridor around a municipality's certified ratio, generally 15% above and below the average ratio.
New Jersey example
Gloucester Township's 56.95% ratio produces a certified range approximately 48.41% to 65.49% for tax year 2026.
Official source
https://www.nj.gov/treasury/taxation/pdf/lpt/chap123/2026CH123.pdf
This is a plain-English summary. Rules and dollar amounts change, so check the official source or a professional before you file or sign anything.