# 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.

## Comparing Movie Production Budgets

| Title                                               | US Gross         |
|-----------------------------------------------------|-------------------|
| Apocalypse Now                                     | 78,800,000        |
| Star Wars Ep. V: The Empire Strikes Back          | 290,271,960       |
| Peter Pan                                          | 87,400,000        |
| Raiders of the Lost Ark                             | 245,034,358       |
| Star Wars Ep. VI: Return of the Jedi               | 309,205,079       |
| Scarface                                           | 44,942,821        |
| Star Wars Ep. IV: A New Hope                       | 460,998,007       |
| 10,000 B.C.                                       | 94,784,201        |
| Cloverfield                                        | 80,048,433        |
| 12 Rounds                                          | 12,234,694        |
| 1408                                               | 71,985,628        |

## 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](https://instacharts.io/docs/chart-types/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