For soil, thats simply not necessary. You want to water thoroughly and let it dry most of the way between waterings.
Im a reckless caveman of a grower so i dont ever measure my water but even for seedlings im definitely giving more than 1 or even 2 shotglasses, and then giving them time to drink it and have some evaporate before giving more. Constantly wet soil can lead to issues, some being potentially fatal for your plant.
Ive killed some plants with kindness in my early years, just trying to help keep anyone from doing the same. sometimes less is more.