NH4
# NH4

NH4 or NH 4 or NH-4 may refer to:

* Ammonium, the cation $NH^+$ $_4$ in chemistry
* National Highway 4 (India), new numbering for a National Highway in India
* National Highway 4 (India, old numbering), a major National Highway in western and southern India
* New Hampshire Route 4, a short state highway located in eastern Strafford County, New Hampshire, United States
