A pie chart is a circular graph divided into slices to illustrate numerical proportions. Each slice represents a category’s contribution to the total. The full circle represents 100%, making this chart ideal for showing how a single variable breaks down into components.
However, pie charts should be used with caution: they work best with a small number of mutually exclusive categories (ideally no more than 3–5). Too many slices can make interpretation difficult. A classic example would be showing market share between three main competitors. For instance, if Company A holds 50% of the market and Companies B and C each hold 25%, the pie chart makes this split visually immediate.
Pie charts are popular in business settings for summarizing parts-of-whole, such as budget allocations, demographic segments, or device usage distribution. Their simplicity makes them accessible, but for exact comparisons, bar or column charts are often more precise.