Pepakura sizing help needed

[broodyguitarguy]

This will be my third helmet using this program various but I seem to have hit a snag on this one in particular i sized it with the width of the helmet. I measured out that my head is about 8 inches across. So I went about 8.5 on the scale which I think was around 215 millimeters I can already tell that it's going to be too small for me what did I do wrong how much clearance should I give it? Also should I read measure my head and did I measured wrong I went to ear to ear. Now do I measure one side of the helmet to the other or opening side to the other opening side?

 

[Raquisite]

You should have measured from the bottom of your chin to the top of your head.

 

[broodyguitarguy]

, so use the height measurement?

 

[Raquisite]

, so use the height measurement?

Of course. Yes.

 

[broodyguitarguy]

How much extra should I put on?