Switching

I'm switching Stella (5 years) and Nyx (4 months) to 100% core wellness canned cat food. The directions say 1 can (5.5 oz.) per day per 7-8 pounds. Well, Stella is 8 so that's easy. But Nyx is 4 month, about 12-13 lbs and judging from her huge paws, has quite a lot more growing to do. They are both indoor only so I don't know if the less activity is a factor. I could really use some guidance on how to measure this for  them. I am home all day so I plan on feeding them 3x a day. Any help or suggestions would be appreciated. Thanks.

*Note* they are both spayed

Activity level definitely makes a difference. About a can is going to be approximately the right amount for Stella. Since Nyx is still a growing kitten, she will eat more. At her age, I would feed her as much as she wants for now. Every cat is individual, so just monitor their weight and adjust accordingly.

It says on the packaging to give one 5.5oz. can per 7-8 lbs. Nyx just got weighed yesterday and is exactly 8 lbs (even though I was sure it was more) same as my 5 yr. old cat Stella. I'm trying to take the company instructions in for consideration but have been judging by how the kitties eat. Two days ago I gave them the packaging recommend can of cat food each divided into 2 meals, but  it was to much for them. I have now been feeding them 1/4 a 5.5oz can 3x a day. Stella eats it right up and seems very content with the amount, and Nixie gets the same and eats all but a few licks here and there. I'm trying to get them on a good schedule, so the food only stays down for 30 minutes. Luckily I don't work so I have the time to feed them breakfast, lunch and dinner. They eat the wellness core (grain free) in turkey/chicken and both love it... I do add 2 tsp of very hot water to the wet food to get it warm and a little more wet (this brands canned food is a little dry and stiff) but they just love it.

I decided to switch them cold turkey to all wet food. I've always left kibble out for Stella to free feed if she wanted but has only ate a few pieces a day so it wasn't a big deal for her. However, Nyx has been on a cheap food since she was at the shelter and she seemed taken with the wet food (just gave her about 1 tbsp a day along with the kibble they sent home the first 2 days). Her coat is very dull, she sheds way more then normal, sooo much dander and had been straining to poop (which smelled horrible even for it being poop). So I just decided to switch her immediately. I haven't noticed big improvement yet other then her potty is 150% better. And her stomach handled the fast change perfectly. I'm hoping after a few weeks on this new food her coat and skin will improve. Stella's coat is beautiful, her dander isn't bothersome and ha never had an upst stomach since I have had her on this food for several years.

Wellness is a high calorie food, that is probably why they are getting full on less than a can. On average, owners find the recommended guidelines on the cat food a bit much, especially if their cat is neuetered/spayed.

The can says its 218 calories per can, and they each get 3/4 a can a day. I figure that to be about 163.5 calories per day for each of them. Is that still to much? I can't feed Nyx more because she still leaves a tiny bit in her bowl each time she eats. BTW- I took Nyx to her first vet appointment since coming home and the vet told me she is not 4 months, but more like 6-7. Culd that be the reason she's not eating more than Stella?