[Solved]-chart shows very small pie-Highcharts

Had the same issue when working with mutliple piecharts. Only 1 of the piecharts appeared smaller in size. The reason being max-width was set for the div element. Once I removed the max-width attribute, it worked fine.

<div id = "ab" style="min-width: 310px; height: 400px; max-width: 600px; margin: 0 auto"> 

to

<div id = "ab" style="min-width: 310px; height: 400px; margin: 0 auto"> 

Try setting minimum width and height of the div container where you are generating chart like this

<div id="pie1" style="min-width: 400px; height: 400px; margin: 0 auto"></div>

First of all, define your width / height, secondly you can modify size of chart by parameter:

http://api.highcharts.com/highcharts#plotOptions.pie.size