how do i figure out a serving size?

i am planning to make some turkey chili in the crockpot this weekend. all of the recipes i see tell how many servings it makes, but it doesn't say specifically what size the serving is (i.e. how many ounces or cups). how would i figure this out?

if anyone knows of a site that lists the size of each serving, lemme know! Or if you have your own turkey chili recipe you want to share with the nutrition and serving sizes, that'd be great too!