E5

E5 is an alphanumeric designation used in multiple domains, rather than a single concept. Depending on the field, e5 can refer to a mathematical expression, a military pay grade, a software edition, or various product models. The meaning is determined by context, acronym usage, and regional conventions.

In mathematics, e designates the base of natural logarithms, approximately 2.71828. The expression e^5, or e to the fifth power, equals about 148.413159, and is often written as exp(5) in programming. This value appears in growth models, compound interest, and certain probabilistic calculations.

In the United States military pay grade system, E-5 represents a mid-level noncommissioned officer. Equivalent ranks include sergeant in the Army and Marine Corps, staff sergeant in the Air Force, and petty officer second class in the Navy and Coast Guard. The designation also appears in some allied forces’ pay grade scales. Personnel at this level typically have leadership duties and responsibilities.

Microsoft 365 (formerly Office 365) offers an E5 edition, a higher-tier enterprise plan that combines productivity applications with advanced security, compliance, and communications capabilities. An E5 subscription typically includes core Office apps, Exchange email, Teams, SharePoint, and OneDrive, plus features such as advanced threat protection, data loss prevention, and analytics. E5 is positioned as a premium option alongside lower tiers such as E3 and E1.

Beyond these, E5 serves as a common model or variant code in consumer electronics, automotive parts, and other products. The term’s exact meaning is context dependent and often determined by accompanying letters or numbers.