Let me start by saying an obvious thing: Gauge charts do deserve some recognition. Actually, they deserve a medal – a medal for being the most controversial chart type in history.
When I first saw a gauge chart, I was impressed. They looked pretty cool. Things changed when I got involved with my first BI project. A closer look revealed that these charts are actually pretty tough to look at. But let’s back up and start from the beginning.
Gauge charts allow us to visualize data in a way that resembles a real-life speedometer needle or a regular gauge. They usually display a single key measure. The outer scale of the gauge is often color-coded to provide additional performance context (green for good, red for bad). Below is a typical example: