N.J. Stat. Ann. § 51:1-3

The inch-pound system of weights and measures in customary use in the United States and the metric system or System International (SI) of weights and measures are jointly recognized, and one or the other, or both, of these systems shall be used for all purposes in this State. The definitions of basic units of weight and measure, the tables of weights and measures, and the weights and measures equivalents, as published by the National Bureau of Standards, are recognized and shall govern weighing and measuring equipment and transactions in this State. It is the intent of the Legislature that nothing in this section shall mandate the exclusive use of SI; however, its use within this State is encouraged.