The "M" in the titles refers to the baking chips’ count per pound. So for example, 1M relates to 1000 chips per pound whereas 4M baking chips have a slightly smaller size and you can get 4 times the amount for a total of 4000 chips per pound. 1M is typically regarded as a standard size. Number values below 1 will have a larger size diameter and less chips per pound, whereas numbers greater than 1 will be smaller in diameter but you'll get more chips per pound. The graphic below allows you to see the difference between the many sizes we carry on our site.