Pie Chart

A pie chart is a part-to-whole plot — a circle divided into slices whose angles encode share of a total, so mix at one moment reads as portions of one whole rather than lengths from a baseline.

The pattern is share of one whole: use when users need to see how a few categories split a single total. Unlike a bar chart, comparison is angular rather than aligned to a shared baseline. Unlike a line or area chart, the series is a snapshot mix, not change along an ordered axis.

Also known as

• Circle chart — the same circular plot of proportional slices

Component Anatomy

Common use cases

Use a pie chart when users need to read a snapshot mix as shares of one total:

• Traffic mix — browsers, devices, or channels as a share of visits
• Revenue split — plan tiers, regions, or products as a share of the quarter
• Survey composition — how respondents split across a small set of options
• Capacity — used vs remaining seats, storage, or budget
• KPI donut — a total in the hole with the mix as a ring around it

Avoid a pie chart when there are more than a handful of slices (use a bar or a table), when users must compare close values (aligned bars beat angles), or when the question is trend or ranking (use a line or a bar). Do not use a pie when the parts do not add to a meaningful whole. Do not explode every slice; a pulled-out sector only helps if one category is the point.

Default pies fill to the center. A donut sets an inner radius so the hole can hold a Label for the total. Stacked pies nest a second ring for a second series or a hierarchy. Pair a Tooltip and Legend on dashboards; add Labels on slices when there are few enough to read; use an active Sector when one category is selected.