Gauge chart

A gauge chart shows one number against a scale — usually as a semicircular arc with a filled portion indicating the current value. It's modeled after a car's speedometer, and it answers one question at a glance: "Are we doing well or badly right now?"

When to use it

Use a gauge when all three of these are true:

1. You have a single value to display. One number, not a series. If you have three related metrics, use three separate gauges side by side, not a line chart.
2. That value has a meaningful scale. There's a known minimum and maximum — a budget ceiling, a capacity limit, a target goal. A number floating without bounds (like "total revenue ever") doesn't belong in a gauge.
3. The reader needs to judge status, not precision. Gauges are great for "we're behind / on track / ahead." They're terrible if you need to read off an exact number.

Common uses: progress toward a quarterly goal, fundraising thermometers, server CPU load, fuel level, customer satisfaction score.

Example data

A gauge chart is configured, not plotted from a table the way a bar chart is. Here's what you need to specify for a quarterly revenue gauge:

Setting	Value	What it means
Minimum	$0	Bottom of the scale (arc starts here)
Maximum	$1,200,000	Top of the scale (arc ends here)
Target	$1,000,000	The goal — usually marked on the arc
Current value	$680,000	Where the needle (or fill) points
Danger zone	$0 – $500k	Colored red on the arc
Warning zone	$500k – $800k	Colored amber on the arc
Success zone	$800k – $1.2M	Colored green on the arc

If you're building a dashboard with several gauges, you'd just repeat this structure for each metric:

Metric	Current	Target	% of target
Revenue	$680k	$1M	68%
New customers	142	200	71%
Customer satisfaction	4.3	4.5	96%
Feature adoption	38%	60%	63%

How to read it

A gauge is deliberately low-information — that's its strength. When you look at one, you should do exactly two things:

1. Glance at the fill position. Is the arc mostly empty, halfway, or nearly full? That's the whole point.
2. Glance at the color zone the value falls into. Red, amber, green is near-universal — readers interpret it without thinking.

The exact number should also be printed in the center of the gauge. If the reader has to squint at the arc to estimate the value, the chart has failed at its job.

A common mistake is treating gauges like a line chart and expecting to see history. Gauges show right now. If you need to show how you got here, pair the gauge with a small sparkline underneath, or switch to a line chart entirely.

How to build one

In a spreadsheet (Excel or Google Sheets)

• Google Sheets has gauge charts built in: Insert → Chart → Chart type → Gauge. Point it at a cell containing your current value and configure min/max/zones in the chart editor.
• Excel doesn't have a native gauge. The common workaround is a "doughnut + pie" combo chart: a half-doughnut for the colored zones, overlaid with a single-needle pie chart. It's fiddly — if you have the option, put the value in a big cell with conditional formatting instead. The information gets through just as well.

With code (for a dashboard or report)

Most libraries render a gauge from a minimal config object. The pattern is always: value, min, max, and optional thresholds.

// Example using a library like Chart.js, Plotly, or ApexCharts
const gauge = {
  value: 680000,
  min: 0,
  max: 1200000,
  target: 1000000,
  zones: [
    { from: 0,      to: 500000,  color: "#f43f5e" },
    { from: 500000, to: 800000,  color: "#f59e0b" },
    { from: 800000, to: 1200000, color: "#10b981" },
  ],
};

Tips

• Always print the number in the center. The arc is for glanceability; the number is for anyone who actually needs to know the value.
• Use at most 4 gauges in one view. More than that and the dashboard becomes noise — consider a table with conditional-formatted cells instead.
• Pick zone thresholds that mean something. "Red below 80% of target" is meaningful. "Red below 50" because 50 is a round number is not.
• Don't use a gauge if lower is better and the reader might forget. A gauge of "average support response time" where the goal is low is easily misread. Flip the metric (e.g., "% of tickets answered within 2 hours") or use a different chart.
• A gauge wastes space on one number. If the number is the star of the dashboard, a large styled text callout often works better — no arc, no scale, just the value in big type with the target underneath.