Gauge and NPS

[Wilco()]

I am trying to create a gauge (http://chandoo.org/wp/2008/09/09/excel-speedometer-chart-download/).

Which seems to go okay.

My challenge is to create a gauge for NPS score. This is a value between -100 and 100.

What is the correct value for the table "blank area"?

 

[Luke M]

The range of your gauge is 200, so the 'blank' area would be 200. To translate from your actual data to the chart, you'll need to convert from a -100/100 scale to a 0/200 scale. See attached.