It depends on how much water the cat drinks and eats throughout the day. Most cats border on dehydration, especially if kept on dry food (straight from my vet, kay!). They should be urinating about as much as they drink. So if they drink a cup of water a day, that's how much they'll urinate. Merlin scared the heck outta me when I got him because he was drinking upwards of two cups of water a day, and urinating about as much (5 to 6 times a day). I thought he was diabetic, but after they ran tests to confirm he wasn't, the vet told me I should be really happy because he'll have less problems because he's so hydrated. (Less of a chance of kidney and bladder stones, and such.)
Thanks, but let me try this from a different direction.
I estimate Nano to be consuming about 250 mL (= 1 cup = 8 fluid oz) of water a day. (So Nano is urinating half of what Merlin is doing.) She is 6-8 year old female cat who weighs 14 lbs but I am going to put her on a canned food diet to get down to 11-12 lbs. Is 250 mL of water going through her system each day good enough or should I try to get her to take more?
Is there some formula for cats? For instance, humans are supposed to drink half an ounce per day for each pound they weigh.
There are no emergencies or health problems here. I am just asking for curiosity and information.