Generally men start at 7" for small wrists, 8" for medium wrists and 9" for large wrists.
Typically the average male is a 8" wrist.
Start at 6" for small wrists, 7" for medium wrists and 8" for large wrists.
Typically the average women is a 7" wrist.
Wrap a cable/ string around your wrist and loosely pinch both ends together.
Keep hold of the connecting point and place your cable/ string next to a ruler/ tape measure to find the correct length for you.