Such a chart is possible to achieve by using the innerSize option. It is not available yet (currently on a master branch) but it will be available in the next release of Highcharts. It is a new property that, as the name suggests, allows to set the inner size for a pane (similarly to the pane's size option). In case when the innerSize is percentage, it is a percentage of the pane's size. Of course the calculation for the calm sector (also the percentage label) must be done by a user as the innerSize determines an empty area in the center of a pane only. Here is the example: https://jsfiddle.net/BlackLabel/x41gjr0z/.
Such a chart is possible to achieve by using the innerSize option. It is not available yet (currently on a master branch) but it will be available in the next release of Highcharts. It is a new property that, as the name suggests, allows to set the inner size for a pane (similarly to the pane's size option). In case when the innerSize is percentage, it is a percentage of the pane's size. Of course the calculation for the calm sector (also the percentage label) must be done by a user as the innerSize determines an empty area in the center of a pane only. Here is the example: https://jsfiddle.net/BlackLabel/x41gjr0z/.