You don’t always need to know exactly how many beads you’ll need for a necklace. But sometimes you do. Stuller, a wholesale jewelry supply company, recently developed a series of charts showing the number of beads per inch required to complete necklaces of varying lengths. I’m reprinting them entirely below. Be sure to remember that some variation will occur with knots and clasps, however, in general, you add about an inch for every 16″ of knotted beads.
Here are the charts. Print them out for future reference, if you desire.
Here is the chart for knotted beads per inch. The Stuller people used a #5 cord, however, this is really a good indication of what you’ll need. The second chart is for unknotted beads per inch (BPI).