Part of a whole
Stacked bar chart
Adds series within each category to show totals and their components.
- Chart
- Composition
- Comparison
What it answers
What makes up each category total?
- Shape
- Segmented horizontal bars
- What it shows
- Total size and component contribution.
Example: Skye Ascent Ltd
The question
How will Skye Ascent Ltd’s costs grow, and which costs drive the growth?
Skye Ascent Ltd costs, 2025 actual and 2026 to 2028 plan
Skye Ascent Ltd is a fictional company created for Insyt.
The misleading version
Same question, drawn badly
Stacking two percentages that do not add up
What goes wrong. The two parts are different measures with different bases. Their sum of 113.6 is not a real total. Show them as two separate figures.
When to use it
Use it when
Showing totals and a few additive components.
Avoid it when
When precise comparison of middle segments is essential.
How to read it
Compare full bar lengths for totals and coloured segment lengths for components.
Note
Negative values need explicit stacking rules.
The data you need
- Layout
- Long table
- Fields
- Category or ordered position: text/date; Series: text; Value: number
- One row is
- One series value within one category or position. What is the grain?
- Rules
- Use one value per category-series pair after aggregation. Define category and series order.
- Optional
- Wide alternative: Category,North,South with one row per category.
- Preparation
- Validate the input grain and missing values. Use one value per category-series pair after aggregation. Define category and series order.
- Units
- Use the measured variable's stated unit consistently. No denominator is implied unless the value is a rate or proportion.
Worked example
Data A: North=30, South=45; B: North=34, South=40. Stack components. Totals are 75 and 74 although composition differs.
| Category | Series | Value |
|---|---|---|
| A | North | 30 |
| A | South | 45 |
| B | North | 34 |
| B | South | 40 |