In the image above you will find a 6mm bracelet (left) and a 8mm bracelet (right) with coins for comparison.
If the bracelet is a gift and you do not want to ask the recipient to measure their wrist, keep these sizes in mind. Most commonly:
To determine your wrist size for a mala bracelet, use a flexible measuring tape and wrap it around the smallest area of the wrist or where your bracelet will rest.
If you do not have a measure tape, you can use a piece of string and wrap it in the same way, then lay the string next to a flat ruler.