Introduction to Sankey Diagrams

What is a Sankey diagram?

A Sankey diagram is a type of flow diagram where the “flow” is represented by arrows of varying thickness, depending on the quantity of flow.

They are often used to visualize energy, material, or cost transfers and are especially useful in demonstrating proportionality to a flow where different parts of the diagram represent different quantities in a system.

Probably the most famous example of a Sankey diagram is Charles Minard’s Map of Napoleon’s Russian Campaign of 1812.