Measuring your wrist
Because bracelets have different shapes and sizes of materials used in their designs, the only accurate measurement of the bracelet length is the ID, or inside diameter as it sits against your skin. That is the measurement I display using my bracelet mandrel. You cannot measure a bracelet that fits you well and use that measurement to determine if a different bracelet will be the right length.
make sure the palm of your hand is facing up
open your hand (this will ensure you get the real size of your wrist when it’s the largest)
snuggly wrap a measuring tape around your wrist
read the size on the measuring tape, preferably in inches
The most accurate way to measure your wrist is by using a cloth tape measure. If that isn't available, you can cut a thin strip of paper and wrap it around your wrist. Mark it where the ends meet, then lay it down on a ruler to see your wrist length.
Fit example #1: 6 3/4" ID bracelet on a 6 1/4" wrist
Fit example 1 shows a looser fit, with "drape" or space, sitting comfortably on the wrist without being sloppy
Fit example #2: 6 1/4 to 6 3/8" ID bracelet on a 6 1/4" wrist
Fit example 2 shows a snug fit, yet still with a bit of "drape" or space, sitting comfortably on the wrist