Resources · Guide
First think about what you want to show —comparison, trend, proportion…— and that almost picks the chart for you. And when in doubt: bars or lines, which are understood at a glance. Pies, worse.¹
The workhorse: together with lines, they solve 8 out of every 10 charts you'll make. For comparing how much each thing sells, nothing reads faster.
"Which channel brings in the most revenue?"
The eye follows the line on its own and sees the trend effortlessly.² It's ideal for watching how something evolves over time and for comparing one year against another: one line per year.
"Are sales growing in 2025 vs 2024?"
Shows how a total that adds up to 100 % is split. It's the most misleading chart: the eye is terrible at measuring the slices of a pie.¹ Use it with care.
"What share does each channel have of the total?"
Crosses two figures (for example price and volume) and lays bare who falls outside the norm. If you color each group, it's the natural way to split your customers into profiles.
"Into which groups do my customers segment?"
Encodes intensity by color over a matrix (category × period) or a map. Perfect for spotting hot zones at a glance.
"Which category and month concentrate the sales?"
Shows a hierarchy with proportion by nested area: category → brand → product. Area is less precise than length, so use it for the big picture, not for fine figures.
"How is my revenue split by category and brand?"
Less common types, but useful when the objective calls for them. Remember: the more exotic, the easier to misread.
Trends emphasizing accumulated volume or temporal composition (stacked).
Beware: several stacked areas read poorly.
Multivariate: X, Y, size and color (3-5 dimensions). Useful in marketing.
Beware: area is imprecise; >6 variables overloads it.
Distribution of a quantitative variable: frequency by range.
Beware: adjacent bars (quantitative) ≠ separated bars (categorical).
Compact distribution: median, quartiles and outliers. Good for comparing groups.
Beware: not very intuitive for a non-technical audience.
Correlations across many variables at once. An exploration tool (EDA).
Beware: too dense for executives.
Geographic distribution: color by region. Always in rates or ratios, never absolutes.
Beware: large, sparsely populated regions dominate the map.
Movements between locations: routes, logistics, origin-destination.
Beware: too many flows = an unreadable blob.
Relationships and flows: fraud (force-directed), org chart (tree), supply chain (Sankey).
Beware: unreadable without grouping or filtering.
Term frequency in text (reviews). Basic sentiment once stopwords are removed.
Beware: indicative only, not suitable for rigorous analysis.
A single key figure read at a glance, in the top-left of the report. Always with trend + target + period — a number on its own says nothing.
Beware: "Margin 18 %" tells you nothing; "Margin 18 % ▲ +3pp vs quarter · target 15 % ✓" does.
Start on the left (what you want to show) and let the middle column decide.
| Goal | Chart | Watch out for |
|---|---|---|
| Compare categories | Bars (horizontal if labels are long) | Pie >6; 3D; truncated axis |
| Time trends | Lines (area if volume matters) | Spaghetti → small multiples |
| Part-to-whole proportion | Pie ≤5-6; otherwise, bar | Imprecise angle |
| Correlation, 2 vars | Scatter | The average misleads; look at the scatter³ |
| Multivariate, 3-5 | Bubbles | Imprecise area |
| Distribution | Histogram / boxplot | Confusing it with bars |
| Geography (region) | Choropleth (rates) | Absolutes / large regions |
| Geography (movement) | Flow map | Blob |
| Intensity | Heatmap | Imprecise color |
| Relationships / network | Graph (Sankey / tree) | Unfiltered = unreadable |
| Hierarchy | Treemap / sunburst | Imprecise area |
| Text | Word cloud | Indicative only |
| Key KPI | BAN (+ context) | A lone number |
Choosing the right chart is half the job. The other half is not lying with it. Continue with the best-practices guide.
References
For anyone who wants to dig deeper. The main text is in plain language on purpose; here are the sources behind each idea.