The fonts were created using [IcoMoon](http://www.icomoon.io “IcoMoon”). The SVG they were created from have no extra space around them and they appear to display correctly in the IcoMoon dashboard.
It is very odd because a couple of days ago I created a font and everything was working correctly. I created one just today and I can’t get the alignment to work correctly.
IcoMoon’s documentation attempts to explain the metrics and it seems it should be centered by default, but I’m not sure.
[IcoMoon Documentation](http://icomoon.io/#docs/font-metrics “IcoMoon Documentation”)