RESOURCES

Visualisation Guide

Pick the visual that answers your question, and draw it so nobody misreads it.

ABOUT THIS GUIDE

Why Chart Choice Changes the Answer

The same figures can be read accurately or misread badly, depending on how they are drawn. This guide covers forty-six visual types, each with what it is for, when to use it and when to choose something else.

Some comparisons are easier to see1

People judge position along a common scale most accurately, then length, then angle and area. That is why a bar chart usually beats a pie chart, and why area-based visuals need care.

The question decides the chart

Comparing categories, showing change over time, showing parts of a whole and showing a relationship are different jobs. Start with the question, then pick the visual.

Every entry says when not to use it

Knowing when a chart stops working matters more than knowing what it is called, so each one names the case where you should choose something else.

Linked to the glossary

Every visual links to its glossary term, where you will find the definition, why it matters and an explanation written for your role.

Sources: 1 Cleveland, W. S. and McGill, R. (1984), ‘Graphical Perception: Theory, Experimentation, and Application to the Development of Graphical Methods’, Journal of the American Statistical Association 79(387), 531–554, which ranks position, length, angle and area judgements by how accurately people make them. 2 Heer, J. and Bostock, M. (2010), ‘Crowdsourcing Graphical Perception’, ACM CHI, 203–212, which repeated those experiments at scale and found the same ordering. Recommendations here are ours, and the choices they support are judgement calls rather than rules.

START WITH YOUR QUESTION

What Do You Want to Show?

The right visual depends on the question you are answering. Pick one to see the visuals that fit.

OR START FROM YOUR DATA

What Does Your Data Look Like?

If you know your columns better than your intent, start here instead. Pick the shape that matches what you have, and the visuals that fit will show below.

Showing all 46 visuals

Comparing categories

Bar Chart

Values for different categories as horizontal bars.

Use It For
Comparing categories, especially with long labels or many items.
Choose Another Visual When
You need to show change over time.
Look it up in the glossary
Comparing categories

Column Chart

Values for categories as vertical columns.

Use It For
Comparing a small number of categories or periods.
Choose Another Visual When
You have more than about ten categories.
Look it up in the glossary
Comparing categories

Grouped Bar Chart

Two or more series side by side for each category.

Use It For
Comparing a few series across the same categories.
Choose Another Visual When
There are too many series to read at a glance.
Look it up in the glossary
Comparing categories

Lollipop Chart

Values as a line ending in a dot.

Use It For
Comparing many categories with a cleaner look than bars.
Choose Another Visual When
Precise values matter more than the overall ranking.
Look it up in the glossary
Comparing categories

Bullet Chart

Actual performance against a target and ranges.

Use It For
Tracking a KPI against its goal in a small space.
Choose Another Visual When
Your audience is unfamiliar with the format.
Look it up in the glossary
Comparing categories

Dot Plot

Values as dots on a shared scale.

Use It For
Showing the gap between two values for each category.
Choose Another Visual When
You need to show totals or parts of a whole.
Look it up in the glossary
Comparing categories

Table

Exact values in rows and columns.

Use It For
People need to look up precise numbers.
Choose Another Visual When
The goal is to reveal a pattern quickly.
Change over time

Line Chart

How a value changes across time.

Use It For
Showing trends across many time periods.
Choose Another Visual When
Your categories have no natural order.
Look it up in the glossary
Change over time

Area Chart

A trend with the space below the line filled.

Use It For
Emphasising the size of change over time.
Choose Another Visual When
Several overlapping series hide each other.
Look it up in the glossary
Change over time

Sparkline

A tiny line chart without axes.

Use It For
Adding trend context next to a number or in a table.
Choose Another Visual When
Readers need exact values or scales.
Look it up in the glossary
Change over time

Slope Chart

Change between two points in time.

Use It For
Comparing before and after for several items.
Choose Another Visual When
You have more than two time points.
Look it up in the glossary
Change over time

Step Chart

Values that change at specific moments.

Use It For
Showing prices, rates or levels that jump.
Choose Another Visual When
Values change smoothly and continuously.
Look it up in the glossary
Parts of a whole

Stacked Bar Chart

Totals broken into their parts.

Use It For
Comparing totals and the biggest part within them.
Choose Another Visual When
Readers need to compare the middle segments.
Look it up in the glossary
Parts of a whole

100% Stacked Bar Chart

Each category’s mix as percentages.

Use It For
Comparing proportions across categories.
Choose Another Visual When
The actual totals matter.
Look it up in the glossary
Parts of a whole

Pie Chart

How a whole divides into slices.

Use It For
Showing two or three parts of one whole.
Choose Another Visual When
You have many slices or similar sizes.
Look it up in the glossary
Parts of a whole

Donut Chart

A pie chart with space in the centre.

Use It For
Showing a simple split with a total in the middle.
Choose Another Visual When
Precise comparison between slices matters.
Look it up in the glossary
Parts of a whole

Treemap

Parts of a whole as nested rectangles.

Use It For
Showing many parts or a hierarchy at once.
Choose Another Visual When
Small differences between parts matter.
Look it up in the glossary
Parts of a whole

Waterfall Chart

How increases and decreases build a total.

Use It For
Explaining what drove a change, such as profit bridges.
Choose Another Visual When
There is no clear start and end value.
Look it up in the glossary
Parts of a whole

Funnel Chart

Values dropping through the stages of a process.

Use It For
Showing conversion through steps, such as a sales pipeline.
Choose Another Visual When
Stages are not sequential.
Look it up in the glossary
Spread

Histogram

How often values fall into ranges.

Use It For
Understanding the shape and spread of one measure.
Choose Another Visual When
You are comparing separate categories.
Look it up in the glossary
Spread

Box Plot

The median, spread and outliers of data.

Use It For
Comparing distributions across several groups.
Choose Another Visual When
Your audience is new to statistics.
Look it up in the glossary
Spread

Density Plot

A smooth curve of where values cluster.

Use It For
Comparing the shape of one or two distributions.
Choose Another Visual When
You have only a small amount of data.
Look it up in the glossary
Relationships

Scatter Plot

Each item plotted by two measures.

Use It For
Looking for correlation, clusters and outliers.
Choose Another Visual When
One of the measures is a category.
Look it up in the glossary
Relationships

Bubble Chart

A scatter plot with a third measure as size.

Use It For
Comparing three measures for a handful of items.
Choose Another Visual When
Bubbles overlap heavily or sizes are similar.
Look it up in the glossary
Relationships

Heatmap

Values as colour across a grid.

Use It For
Spotting patterns across two categories, such as day and hour.
Choose Another Visual When
Readers need exact values.
Look it up in the glossary
Relationships

Combo Chart

Columns and a line on shared or dual axes.

Use It For
Showing a volume alongside a rate, such as sales and margin.
Choose Another Visual When
Two scales would confuse the message.
Look it up in the glossary
One number

KPI Card

One key number with context.

Use It For
Highlighting a headline figure and its change.
Choose Another Visual When
You need to explain why the number moved.
Look it up in the glossary
One number

Gauge

Progress towards a target on a dial.

Use It For
Showing a single percentage against a goal.
Choose Another Visual When
Space is limited or you have many metrics.
Look it up in the glossary
Geography and Flow

Filled Map

Values shaded across regions.

Use It For
Showing how a measure varies by location.
Choose Another Visual When
Region size would distort the message.
Look it up in the glossary
Geography and Flow

Sankey Diagram

Flows between stages as bands of varying width.

Use It For
Showing where volumes come from and go to.
Choose Another Visual When
There are too many flows to follow.
Look it up in the glossary
Change over time

Gantt Chart

Tasks shown as bars across a timeline.

Use It For
Planning projects and showing overlaps, dependencies and delays.
Choose Another Visual When
You need to compare values rather than dates.
Look it up in the glossary
Comparing categories

Pareto Chart

Bars sorted largest to smallest with a running total line.

Use It For
Finding the few causes behind most of a problem.
Choose Another Visual When
Categories have no natural ranking.
Look it up in the glossary
Comparing categories

Radar Chart

Scores across several measures shown as a shape on radiating axes.

Use It For
Comparing strengths and gaps across a handful of measures.
Choose Another Visual When
Readers need precise values.
Look it up in the glossary
Change over time

Control Chart

A line with an average and upper and lower limits.

Use It For
Checking whether a process is stable over time.
Choose Another Visual When
You only have a few data points.
Look it up in the glossary
Spread

Violin Plot

Box-plot detail with a smooth shape showing where values cluster.

Use It For
Comparing the shape of distributions between groups.
Choose Another Visual When
Your audience is new to statistics.
Look it up in the glossary
Comparing categories

Word Cloud

Words sized by how often they appear.

Use It For
Giving a quick feel for themes in comments or feedback.
Choose Another Visual When
You need accurate comparisons between words.
Look it up in the glossary
Comparing categories

Small Multiples

A grid of small charts with the same scale, one per group.

Use It For
Comparing patterns across many regions or products.
Choose Another Visual When
There are only one or two groups.
Look it up in the glossary
Comparing categories

Matrix Visual

A table grouped by rows and columns with subtotals.

Use It For
Showing detailed figures with totals, such as sales by region and month.
Choose Another Visual When
The goal is to reveal a trend quickly.
Look it up in the glossary
Parts of a whole

Decomposition Tree

A total broken down step by step into what drives it.

Use It For
Exploring why a number is high or low.
Choose Another Visual When
You need a fixed summary for a printed report.
Look it up in the glossary
Comparing categories

Diverging Bar Chart

Bars extending either side of a centre line.

Use It For
Showing gains and losses, or agreement and disagreement.
Choose Another Visual When
All values are positive.
Look it up in the glossary
Comparing categories

Ribbon Chart

Stacked columns whose ribbons show how the ranking changes between periods.

Use It For
Showing which category leads each period, and how positions swap.
Choose Another Visual When
You only need totals, not changes in ranking.
Look it up in the glossary
Where or how things flow

Bubble Map

A map with circles sized by value at each location.

Use It For
Comparing size by place, when regions differ wildly in area.
Choose Another Visual When
Exact boundaries matter more than volume: use a filled map.
Look it up in the glossary
Parts of a whole

Waffle Chart

A grid of squares where each square is a share of the whole.

Use It For
Showing a percentage in a way people can count square by square.
Choose Another Visual When
You have more than three or four categories.
Look it up in the glossary
Change over time

Bump Chart

Lines that track rank rather than value over time.

Use It For
Showing who moved up or down a league table over time.
Choose Another Visual When
The size of the gap matters, not just the order.
Look it up in the glossary
Parts of a whole

Sunburst

Rings that break a total down level by level, from the centre out.

Use It For
Showing a hierarchy, such as region, then country, then site.
Choose Another Visual When
Two levels or fewer: a treemap or bars will be clearer.
Look it up in the glossary
Comparing categories

Multi-Row Card

Several key figures stacked in one block, each with its label.

Use It For
Showing four or five headline numbers together on a dashboard.
Choose Another Visual When
One number carries the message: use a KPI card.
Look it up in the glossary
FORMATTING AND CRAFT

Choosing the Chart Is Half the Job

Most charts that mislead are the right type, drawn carelessly. These nine rules cover where it usually goes wrong, with the same data drawn both ways.

Axes

Start bars at zero

A bar chart says "this one is twice as big" through its length. Cut the axis and a 4% difference looks like a doubling. Lines are different: they show change, so they may start near the data.

Avoid
Better
Sorting

Sort by value, not the alphabet

Alphabetical order scatters the story across the chart. Sorting by value puts the answer at the top. Keep the natural order only when one exists, such as months or survey scales.

Avoid
Better
Colour

One colour, one highlight

Six colours make the reader work out what colour means before they can read anything. Use one colour, and a second only for the thing you want noticed.

Avoid
Better
Labels

Label the lines, drop the legend

A legend makes the eye travel back and forth matching colours to names. Put the name at the end of the line instead, and delete gridlines you do not need.

Avoid
Better
Numbers

Round to the decision

£1,284,309.47 is precision nobody acts on. Round to what changes the decision, keep the unit visible, and never mix per cent with percentage points.

Avoid
Better
Dates

Drop the part-period

The current week or month is always incomplete, so the last point falls off a cliff and people think something broke. Cut it, or mark it clearly as partial.

Avoid
Better
Missing values

Zero is not the same as blank

A gap in a line can mean no sales, or no data yet. Plotting blanks as zero invents a crash that never happened.

Avoid
Better
Annotation

Write the takeaway on the chart

If the reader has to work out the point, half of them will work out a different point. One sentence in the corner settles it.

Avoid
Better
Decoration

Nothing that is not data

3D, shadows, gradients and heavy gridlines add ink without adding meaning, and 3D actively distorts the comparison.

Avoid
Better

Printable version: the cheat sheets download on the Templates page includes ten checks before you publish a dashboard.

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