Very nice vid, Opie!

So now I have a 4 inch soft utility shackle...after wrapping round for prussic it'll be < 3 inch

What would be the in the marked distances for each inch increase 3in utility shackle.
This is a 4 inch.
Making markings to make a 5 in, a 6 in, a 7 in, etc??????
Just hit and miss or is this a math formula.....?????
Tom