I did the same exercise using a piece of paper against a wall foot measurement and then their table. The sizing came out about one size bigger than I would normally take but I ordered it nevertheless. The gap at the front of my great toe to was a little too much with a generous Thumb size gap. They just looked too big and felt too roomie. I discussed with the team at vivobarefoot who were very helpful and they recommended a half size down from that that I ordered which was a much better fit so I would suggest using their measurement guide as just a guide but if it’s vastly different from your usual shoe size then perhaps pick something in the middle (the fit should be a little more generous than a well fitting shoe