Here is a Tamagotchi Tama-Go growth Chart!
And here is a guide:
Good Care: 4/5 hungry hearts, 4/5 happy hearts, almost light weight, 10/15 to 12/15 training, almost high friendship
Okay Care: 3/5 hungry hearts, 3/5 happy hearts, average weight, 7/15 to 9/15 training, medium friendship
Bad Care: 2/5 hungry hearts, 2/5 happy hearts, almost heavy weight, 4/15 to 6/15 training, almost low friendship
Horrible Care: 1/5 hungry hearts, 1/5 happy hearts, heavy weight, 0/15 to 3/15 training, low friendship