• Short-Range Ballistic Missile (SRBM):  < 1,000 km

• Medium-Range Ballistic Missile (MRBM): 1,000 - 3,000 km

• Intermediate-Range Ballistic Missile (IRBM): 3,000 - 5,000 km

• Intercontinental Ballistic Missile (ICBM): >5,550 km

This is the classification used by the United States.