Sankey Diagram
Also known as: Sankey chart · Sankey graph · flow diagram
A Sankey diagram is a type of flow chart where the width of each arrow or band is proportional to the quantity it represents, making it easy to spot where the biggest flows go. Originally invented in 1898 to chart steam engine efficiency, the format found a second life on Reddit's r/dataisbeautiful and eventually went viral as a meme template in early 2024 after adult content creator Aella posted one charting her birthday gangbang, sparking a wave of comedic imitations on X.
Overview
A Sankey diagram visualizes how quantities flow from one category to another, with the width of each connecting band scaled to the size of what it represents1. Nodes sit on either side (or in multiple columns), and the links between them branch, merge, and narrow as values split across categories. The result is an instantly readable picture of where the biggest portions end up and where the smallest trickle off.
What makes the format so meme-friendly is its dramatic visual storytelling. A single thick band splitting into dozens of tiny slivers tells you everything about a process without needing a single number. When applied to absurd personal data, like dating app outcomes or party attendance, the effect lands somewhere between infographic and punchline4.
Irish captain Matthew Henry Phineas Riall Sankey created the first Sankey diagram in 1898 as part of a report titled "The Thermal Efficiency of Steam Engines," where he used the format to show how energy moved through a steam engine and where it was lost1. The concept built on earlier flow visualization work. Charles Minard had used a similar technique as early as 1844, and his famous 1869 map of Napoleon's Russian campaign of 1812 is often considered one of the greatest statistical graphics ever made, predating Sankey's formalization by nearly 30 years1.
For most of the 20th century, Sankey diagrams stayed in science and engineering. The U.S. Energy Information Administration uses them annually to illustrate national energy production and consumption, and Lawrence Livermore National Laboratory maintains a collection of energy and carbon flow Sankey diagrams1.
Origin & Background
How It Spread
How to Use This Meme
Creating a meme Sankey diagram typically follows this pattern:
Pick a personal or absurd topic where quantities split across outcomes. Dating app results, job applications, party RSVPs, or any process with a dramatic funnel works well.
Use a Sankey diagram generator like SankeyMATIC, Google Charts, or dedicated tools. Feed in your categories and flow values.
Make the contrast dramatic. The humor comes from one massive input band splitting into tiny outcome slivers, or from labeling the flows with unexpected categories.
Post with minimal caption. The chart speaks for itself. A deadpan title like "My Tuesday" or "How I spent my birthday" often lands better than over-explaining.
Cultural Impact
Fun Facts
Charles Minard's 1869 Napoleon campaign map used the Sankey technique 29 years before Sankey himself formalized it.
The sankey-diagrams.com blog ran for nearly 15 years and published over 660 Sankey diagrams before its creator retired.
The Tumblr post from 2011 about falling for someone was made as a byproduct of a group project that required Sankey diagram software, and the creator made the personal chart before deleting the software.
A Sankey diagram of how students spell "camouflage" is one of the most upvoted data visualizations in Reddit history with over 25,000 upvotes.
The width of arrows in a Sankey diagram is always mathematically proportional to the quantity represented, meaning you can't fake the visual ratios without breaking the format.
Frequently Asked Questions
References (5)
- 1
- 2I Love Chartsarticle
- 3
- 4Sankey Diagram - Know Your Memeencyclopedia
- 5Sankey diagram - Wikipediaencyclopedia