Surface-to-surface missiles are usually divided into a number of categories:
Different parties break down missile type by the range differently. For example, the United States Department of Defense has no definition for LRBM, and thus defines an ICBM as those missiles with ranges greater than 5,500 km (3500 mi). The International Institute for Strategic Studies also does not define a range for LRBMs, and defines SRBMs as having somewhat shorter ranges than the definition used by the Department of Defense.