When it comes to designing dashboards, people often turn to gauges as a way of representing a single data point that fluctuates over time, like a speedometer in a car.
The gauge is most useful to quickly see a metric in comparison to defined minimum and maximum values.
When to use a gauge visualization
Gauges are a great choice to:
Show progress toward a goal.
Represent a percentile measure, like a KPI.
Demonstrate the health of a single measure.
Display information that can be quickly scanned and understood.
Gauges are ideal for displaying data that:
Has a clearly defined range (minimum and maximum) of values.
Can be represented with a single numeric metric.
Example uses of a gauge
You could set up a gauge that displays the current number of sales of a product in a 24 hour period and the minimum and maximum values could be defined as the least and the most number of sales ever recorded in a 24 hour period.
Another use for this type of widget could be for current visitors on a website and similarly, the minimum and maximum defined as the smallest and largest number of visitors seen in a 24 hour period.
Alternatively, you could be offering a workshop and use the gauge to track sign-ups. You could need a minimum number of users to sign-up before you could host the workshop and also only be able to support a maximum number of users. You could also desire a number of sign-ups in between a minimum and maximum that would be ideal for the workshop, set as your goal.
The minimum and maximum values are automatically set if left blank. In other words, a default value is calculated (based on some rules) for your gauge's "min" and "max" if none is provided.
The following rules (to set minimum and maximum) apply to gauges:
If current value type is a percentage, default min is 0 and default max is 100
If current value type is not a percentage, default min is 0 and default max is set to the closest power of ten higher than current value. With the smallest max being 10
Some examples of the latter:
If current value < 0, max = 10
If current value = 0, max = 10
If current value = 0.4, max = 10
If current value = 4, max = 10
If current value = 40, max = 100
If current value = 100, max = 1000
Default values are set upon saving if no value is manually specified for min / max in the widget setup page.
Note: If you edit a widget saved without a min or a max value, default values will appear in the same way as if they'd been manually configured.
Why our gauge visualization uses only red and green
Geckoboard's gauge features two colors: red and green (through status indicators). This is a deliberate design decision. We use color in our dashboards to highlight things and to draw attention towards them. We believe having a third 'normal' colour state on a gauge takes away a person's ability to spot important changes at a glance.
Tips for creating gauges
Decide on a clear title. The title should be a brief description of the data that you want to show.
Use the Decimal Places feature to manually set the precision of numbers in your widgets, so that you can show the level of detail appropriate for your dashboard.
If needed, you can also override our automatic settings for what abbreviation and unit to show. Abbreviation, Decimal Places and Unit are part of the "Fine-tune" settings.
Abbreviation: Numbers can be shown in their raw state, or as Thousands (K), Millions (M), or Billions (B).
Unit: Allows you to manually enter any prefix or suffix up to 3 characters long. This means if you’d prefer to display your currency differently to our default option you now can. As examples you might want Swedish Krona to show as 100 Kr instead of SEK 100, or New Zealand Dollars to just have the $.