Old cat new diet

I've noticed my 13 yr old cat was slowing down. I felt bad that she's kinda been ignored the past few years (we had 3 children in the last 5 years and before that she was my baby).
I did some research and decided to switch her to a wet food diet. her previous diet was unlimited friskies kibble and a 3 oz can of fancy feast gravy lovers which she would only lick the gravy off of. Now she gets about 6oz of pate style wet food divided into 4 meals. I've been using fancy feast classics, Buju and ziggie, iams, and Sheba as they are sold at our grocery store. But I really have no idea how much I should be feeding her. She's a very small cat and has never been fat. I estimate her around 8 lbs or under. Any advice is welcome.

After weighing her by holding her on a bathroom scale and subtracting my weight, she is approximately 8.6 lbs.

You just want to feed enough calories daily. The typical recommendation is 20 to 25 calories per pound of  ideal body weight daily. For an 8 lb cat this is roughly 160 to 200 calories daily. Some cats may need a little more or less so just adjust to your cat.

You can find out calorie content per can on these charts:

http://catinfo.org/docs/FoodChartPublic9-22-12.pdf

http://www.petobesityprevention.org/wp-content/uploads/2010/05/Cat_Canned_Pouch_Foods.pdf

I'd keep feeding 4 times a day if that works out for your cat. Small frequent meals keeps tummies happy.

Thanks! That was super helpful! Looking at her cans, she's getting aproximately 180 cal in wet food daily. So in the range you stated. I guess I'll keep this up a while and see how she's doing in a few weeks.

Thx for the links I was just wondering how much my cat should eat