I have 3 bags of dry food from 3 different brands, 2 grain free and 1 with rice. All 3 bags advise to use around 38g-44g for an indoor sterilized cat of 4kg heavy. I can’t find caloric information for my food so I just go with the advised values and adjust as needed. 1 cat is given slightly less because she’s really lazy and doesn’t move much and the other 1 gets more because she’s super hyper. Both cats have not had noticeable changes in size and when you touch their ribs you should be able to feel a bit of fat if they aren’t under eating.

What surprised me the most was how little the portion sizes were when I measured their weights. I used to give my first cat 2 scoops (using a protein shake scoop) of food a day which looked like a good healthy amount to my eyes because it filled the bowl and looked normal. She gained a ton of weight. 40g of food isn’t even 1 full scoop and splitting it over 3 meals means that the bowl looks really empty with only one small layer of food. I don’t measure the food anymore now because I’ve gotten used to what the right amount looks like but it’s a big difference from what I thought it should look like. If you saw me feed them that little you would probably think I’m starving them but I’m not.