Stop 05 · Data VisualizationTopics · 7/10

Bar / Line / Scatter / Pie Charts (When to Use Each)

In short

These four charts cover most of what you'll ever need. Know exactly when each one shines, and when it misleads, and you'll rarely need anything fancier.

The four foundational chart types — bar for categorical comparison, line for trends over time, scatter for relationships between two numeric variables, pie for simple part-to-whole (used sparingly).

The jaadu compares stacks of laddoos and a cake cut into slices at a sweet shop counter.

Think of it like this

At the mithai shop counter

Stacks of laddoos of different heights let you compare quantities at a glance, like bars. A cake cut into a few slices shows shares of a whole, like a pie. But cut the cake into twenty slivers and nobody can tell which piece is bigger.

Watch it happen

Four charts, four jobs

Bar

Line

Scatter

Pie

1/5Bar: compare categories, like sales per city. Sort them and start the axis at zero.

The big ideas

What you need to know

Bar

Best for comparing categories. Horizontal bars work well when labels are long.

Line

Best for trends over time. The x-axis should be evenly spaced time.

Scatter

Best for relationships and spotting outliers between two numeric variables.

Pie

Only for a few parts of one whole. If slices look similar, use a bar instead.

Save yourself the pain

Common mistakes

Oops

Using a line chart for categories like cities.

Do this instead

Lines imply a connection between points. Use bars for unrelated categories.

Oops

Comparing two pies side by side.

Do this instead

Use a grouped or stacked bar chart. Comparing angles across two pies is very hard.

Your mission

One dataset, four charts

~30 min

Quick check

You want to check whether higher-priced products get lower ratings. Which chart?

Go deeper

1Build all 4 chart types from the same dataset and note which communicates best.
2Learn the specific weaknesses of pie charts that make bar charts usually better.
3Practice justifying your chart choice out loud, not just picking by habit.