76-ish pixels per Unit... 0.O ??? (API and Hex Grids)

I discovered something Strange while writing code in the API for weapon ranges: Roll 20 says that there are always 70 pixels per Unit... but there aren't. First of all: I am using a vertical hex grid for my Campaign, and my tokens are set to snap to the hex bounds when moved. Therefore, the exact 'top' and 'left' properties are being set automatically by the UI, not my scripts. I have it set to 1 Unit = 5 feet. I am using the standard distance formula to find the raw distance between two tokens in pixels, which I then convert to feet. The Problem is, that it's not coming out to be 1 Unit = 70 pixels, but rather some non-integer approximately equal to 76 pixels. And worse, the distance between two hexes varies, based on which "direction" one is from the other. Has anyone else observed this? Any explanations?

Oh! Wow. Thanks! ^_^ I think this will help. Do you happen to know how they draw the grid, or calculate the snap-to properties of it?

OR - is there an API function call that comes with Roll20 that I can just pass the two Token references to, and it can return distance in units? Just the way the Rangefinder tool does, but, for my API...

OK thank you Kristin! <3