Chart Axis Labels
Axis labels and titles should make the chart’s scale, categories, and units immediately understandable without repeating metadata already stated elsewhere in the chart.
Label chart axes with the information readers need to interpret the scale, especially units. Avoid duplicating the title/subtitle, and do not add an axis title when the categories or dates already make the axis self-explanatory.
Key details
Important caveats
Category Boundary
An axis that already shows self-explanatory categories or dates may not need a separate axis title; label only what helps interpretation.
Further guidance
Numeric Labels
For percentages or currency, include the relevant symbol directly in numeric axis labels when that is the governing chart convention.
Practical Application
Label an axis when readers need help identifying the variable, measure, or unit. Put units where they apply consistently to the scale, and omit a redundant axis title when category names or dates already make the dimension obvious.
Reader Check
Could a reader interpret both axes—including the unit of measurement—without guessing, and have you removed labels that merely repeat the chart title?
Units
Use an axis title for the unit of measurement when readers need it, while avoiding repetition of information already clear from the title or subtitle.
Worked Example
For a vertical scale showing percentages, use an axis label such as “Share of respondents (%)” if the measure is not otherwise explicit; for a horizontal axis that already lists self-explanatory years, do not add a redundant “Year” title unless your house style requires it.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Chart details: Chart text — ONS Service Manual (opens in a new tab)Office for National Statistics · Chart titles, subtitles, alternative text, figure numbering, data sources, axis titles and axis number labels