@RootBeer flea can fall 200 times it's height and still fine
the one that matter is not how many times it's size it's fall but from how high it's fall even fall from 1000 times of your won size won't really hurt if you only 1 µm tall(1000x1µm=1mm) but falling from 4 meter can hurt us even if it's only about 2 times our height