These shells measure from 1/4" to 1/2" long. The photo shows some of the smallest ones and the larger ones. You will get a mix of both.
A quarter cup will yield several hundred shells.
They are measured, not counted, so you will find some broken ones.However, I have added plenty of extras to make up for any broken ones you find.
These are a rather fragile shell that is easily crushed, so they must be used with care. They would be pretty as a rope or border. Use them in candles or as fillers for tiny vases.