A population pyramid uses back-to-back horizontal bars to display the distribution of a population by age group and gender. The left side typically shows males and the right side females, creating a distinctive pyramid shape for growing populations or a column shape for aging ones.
Mars Mission Proposals: Submitted vs Actually Funded by Decade
Best for
- Comparing distributions across two opposing groups (e.g., male vs female)
- Showing age demographics and population structure
- Highlighting demographic shifts like aging populations
Avoid when
- You only have one group to display — use a standard bar chart
- Data doesn't have a natural opposing pair — use grouped bars
- Categories aren't ordinal — the vertical axis should have a logical order