How many plain and peanut m and ampms fit in quart jar?

The number of plain and peanut M&M's that fit in a quart jar can vary based on the size of the M&M's and how tightly they are packed. On average, a quart jar can hold approximately 150-200 plain M&M's or about 100-150 peanut M&M's due to their larger size. For a more accurate estimate, you could fill the jar with each type separately and count them.