percentstyle

Percentstyle is a formatting concept used in software libraries, data visualization, and typesetting to control how percentage values are displayed. It encompasses rules for numeric representation, the use and position of the percent sign, rounding behavior, and locale-sensitive conventions such as decimal separators and spacing. Depending on the system, percentstyle may be a configurable option, a preset style, or an inline formatting directive applied to numbers in tables, charts, and narrative text.

Common features include precision (the number of digits after the decimal point), rounding method, and whether values are shown as a true percentage (for example, 0.75 becoming 75%) or as a fraction with an explicit percent symbol. It also covers spacing around the percent sign, whether a space is inserted before %, and how negative percentages are displayed (minus sign or parentheses). Locale awareness handles decimal separators (dot vs comma) and thousands separators.

Percentstyle choices can be described as compact versus full, with compact styles favoring shorter representations in dense formats, and full styles prioritizing readability. In data workflows, percentstyle interacts with localization, unit systems, and number format libraries, affecting accessibility and consistency across reports and dashboards.

See also: percentage, number formatting, localization, typography.