Mekko Chart
A Mekko chart, also known as a Marimekko chart, is a two-dimensional stacked bar chart where both the width and height of each bar are proportional to the data. Column width represents the total size of a category, while the height of each segment within that column represents the sub-category’s share of that total. The area of every rectangle is therefore proportional to its absolute value.
Mekko charts excel at comparing the relative size and composition of categories simultaneously.
An example of an embedded Mekko chart
Creating an Effective Mekko Chart
Recommended data types for each axis:
- X-Axis Categorical data (each category becomes a column; column width encodes the category total)
- Y-Axis Numerical values (segment heights sum to 100% within each column)
- Breakdown Axis Categorical data (each unique value becomes a segment within the columns)
Description
- Columns - each column represents one main category; column width is proportional to the category’s total value relative to all categories
- Segments - stacked colored sections within each column; their heights represent the sub-category’s share of that column’s total (always summing to 100%)
- Cell area - the product of column width and segment height; proportional to the absolute value of that sub-category within that category
- X-Axis - lists the main categories; spacing reflects proportional width, not equal intervals
- Colors - each sub-category uses a consistent color across all columns
- Legend - maps each color to its corresponding sub-category
When to Use a Mekko Chart
- Show both size and composition - when you need to convey that one category is larger than another and how each is composed, a Mekko does both at once
- Market share analysis - compare segment share across markets of different sizes in a single view
- Resource allocation - visualize how resources (budget, staff, time) are distributed within departments of different sizes
- Two-level categorical breakdowns - when your data has a natural hierarchy of two categorical dimensions and one numeric measure
When to Avoid a Mekko Chart
- Too many segments - a large number of thin slivers becomes unreadable; group smaller sub-categories into “Other”
- Precise value comparisons - column widths and segment heights are proportional, not absolute; use a table or stacked bar chart when exact numbers matter
- Negative values - Mekko charts are not designed for datasets that include negative values
- Unfamiliar audiences - the dual encoding of width and height is less intuitive than standard bar charts; always include a clear title and legend when presenting to general audiences