Charts for presentations: making numbers readable

The chart itself is not the hard part. The hard part is that the audience cannot zoom, cannot re-read, and is listening to you at the same time. A chart built for a report — many series, a legend, small print — usually fails when it is projected.

1. Make the title the takeaway

“Revenue by quarter” tells the audience what the chart is about. “Revenue grew 23% after the price change” tells them what to see. The title is the only sentence everyone is guaranteed to read, so put the finding there and let the chart serve as evidence.

2. One message per chart

If two findings matter, use two charts. The instinct to combine them — a second axis, an extra series, a small table in the corner — is how a slide becomes something the audience stops reading. A slide can carry one comparison; depth belongs in the appendix or the written report.

3. Size for the back of the room

• Axis labels and data labels should be large enough to read at the projected size — as a rule of thumb, at least the equivalent of 18–24pt on the slide.
• Fewer elements: drop gridlines you do not need, drop the legend if direct labels work, drop the border and background.
• Test at real size. Look at the slide at the size it will actually be shown, not on your laptop while zoomed in.

4. Label directly, highlight deliberately

A legend forces the audience to look back and forth between a colour swatch and a line. A label next to the series removes that step. If one series is the point, give it the strongest colour and leave the rest grey — colour as a spotlight, not as a category for everything.

5. Keep scales consistent across slides

Two consecutive slides with different y-axis ranges can make a flat quarter look like a collapse, because the audience carries the previous scale in their head. If you compare slides, keep the axis and units identical; say so in the subtitle if the scale changes.

6. Annotate the thing you are saying

Point at the finding: an arrow, a bracket, a short note. The audience is listening to you while looking at the chart, and the annotation is what connects the two. Without it, you spend the slide explaining where to look.

7. Export at a resolution that survives projection

A screenshot of a chart in a slide gets blurry on a projector or a large screen. Export at 2× (high-density) and place the image at its intended size. If the chart will be edited later, export an editable Excel file instead of a picture — see the Excel-to-chart guide.

Slide versus written report

A checklist before you present

• Does the title state the finding, not the topic?
• Is there exactly one message?
• Can every label be read from the back of the room?
• Are series labelled directly instead of by a legend?
• Do consecutive slides share the same scale?
• Is the key point annotated?
• Was the image exported at 2× rather than screenshotted?

If you need a chart for the slide right now, paste the table into ChartPaste, pick the type, and download the 2× PNG. The chart-choice guide covers which type fits the comparison you are presenting.