A Sankey diagram shows flows between categories, where the width of each band is proportional to the quantity flowing through it. Thicker bands represent larger flows; thinner bands represent smaller ones. Nodes on the left are sources; nodes on the right are destinations.
Sankey diagrams are excellent for visualising budgets, energy use, time allocation, or any situation where you want to show how a total quantity is distributed across multiple categories and sub-categories.
This diagram type is experimental and requires Mermaid v10.3 or later.
sankey-beta Income,Housing,950 Income,Food,380 Income,Transport,220 Income,Entertainment,150 Income,Savings,300 Housing,Rent,750 Housing,Utilities,200 Food,Groceries,280 Food,Eating out,100 Transport,Public transport,120 Transport,Car costs,100
The source file is plain CSV: each line has a source node, a destination node, and a numeric value. The diagram draws itself from those three columns — no layout instructions needed.
```mermaid
sankey-beta
Income,Housing,950
Income,Food,380
Income,Transport,220
Income,Entertainment,150
Income,Savings,300
Housing,Rent,750
Housing,Utilities,200
Food,Groceries,280
Food,Eating out,100
Transport,Public transport,120
Transport,Car costs,100
```
For more Sankey diagram syntax see the Sankey diagram documentation at mermaid.js.org