It seems silly to post about size but my idea of large and yours is not always the same and if they're not the same the recipe won't yield the same results which could turn it into a huge floppola!
I learned the hard way without even thinking I chopped a large onion
it's what the recipe called for it right.....wrong!!
If you chop 2 of the small onions instead of 2 of the large onions huge difference in measurements. That large onion is about two cups of onion the small 1 cup know make a recipe that calls for two large onions is that 2 cups of onion or four cups yep made that mistake !!!!!!!
2 of the large potatoes made enough mashed potatoes for 5 people where as the red took 5 potatoes to make 5 servings of mashed and the red were fairly large for a red potato.
Same with sweet potatoes oh yea screwed up a recipe big time that called for 3 sweet potatoes I had sweet potatoes everywhere just over powering the rest of the stew.
Every cook has there own idea of what large and small are. I promise to do my best to always have measurable amount in my recipes so you don't have to guess my large.