Cut a long strip of fabric that is double as wide as you want your bracelet and pin in half width ways.
Use a ruler to mark out the inch markings on one side with a fabric pen.
On the other side mark out the centimetre markings.
Fold the fabric the other way over, so that the marking are on the inside, and pin along the edge.
Sew along the edge.
Fold inside out so that the markings are now facing the outside.
Fold under the edges and sew.
Press on snaps at either end using a snapper gun.