Measure with all your hair included (Ex. the bun) if you ain’t to make cornrows.
Measure at least 3 times to get the correct measurements.
The measurements with background color mainly determine the capsize.
Choose the big one when any of the 4 measurements are in between.
5 by 5 closure wigs only have lace covering the forehead and no lace at sideburns, which causes the sideburns of the wig laying behind your own. This is a solution to avoid wefts showing not a size issue.