Compositions

Composition charts show how individual parts make up a whole. They are usually communicating percentages that add up to 100%.

The Stacked Bar Chart

The safest bet for composition. Unlike pie charts, stacked bars can be placed side-by-side to show how a composition changes over time or across categories.

The inherent flaw: Only the bottom segment sits on a common baseline (0). This makes the bottom segment (red) very easy to compare across columns. The middle and top segments are much harder to compare because their starting points shift.

Fix: Put the most important category at the bottom, anchored to zero.

When to use a Pie Chart

Almost never, but if you must, follow strict rules:

1. Max 3 slices. Never more than 5. If you have 20 categories, group them into "Top 3" and "Other", or use a horizontal bar chart.
2. Never 3D. Tilting the pie distorts the area of the slices, rendering the chart actively deceitful.
3. Start at 12 o'clock. Place the largest slice starting at top center, going clockwise.

Treemaps

For hierarchical data (e.g., a file system, or a company budget broken down by department, then team), treemaps use nested rectangles to show part-to-whole relationships across multiple levels.

Next Steps

Generate a distinct set of colors for your composition using the Categorical Palette Generator.