EnUS

enUS is a locale identifier used in computing to denote English as used in the United States. It is commonly written as en-US or en_US in software, websites, and data interchange. In some contexts the form enUS without a separator is also used. The tag combines a language code with a regional variant to guide localization, formatting, and culturally appropriate behavior in applications.

As a representation of American English, en-US follows American spelling and vocabulary conventions, such as color and center rather than colour and centre. Some usage and punctuation preferences also differ from other variants.

Date, time, numbers, and currency: The typical date format is Month Day, Year (July 4, 2025). Times commonly use the 12-hour clock with AM/PM, though 24-hour times appear in technical contexts. Numbers use a decimal point and a comma as a thousands separator. Currency is shown with the dollar sign ($) preceding the amount.

Units of measure: US customary units (inches, feet, pounds) are common in everyday life, though metric units are widely used in science, industry, and international contexts.

Usage in software: En-US tailors user interfaces, sorting, spell checking, currency and date/time formatting, and data validation. In web pages, the HTML lang attribute often uses en-US to indicate language and regional conventions; it can also influence keyboard layouts such as the US keyboard.

Relation to other variants: En-US is part of a family of English locale identifiers; others include en-GB, en-CA, en-AU, etc. They are mutually intelligible but encode regional differences in spelling and conventions.