How Much Wet Food Should I Feed My Cat? (Wet vs Dry)

Wet food labels often say something like “feed one 3 oz can per 3–3½ lb of body weight daily.” That’s a starting point, but it assumes an average cat, and many indoor, neutered cats need less. It also doesn’t help much if you feed both wet and dry. The fix is the same one vets use: count calories first, then turn calories into cans and cups.

How many calories does my cat need?

Vets start with the resting energy requirement (RER), the energy your cat burns at rest:

RER = 70 × (weight in kg)^0.75

Then they multiply by a factor for your cat’s life stage (our post on how many calories a cat needs a day has the full chart by weight, plus kittens and seniors). These factors are from the Merck Veterinary Manual:

Cat	Factor (× RER)
Neutered adult	1.2
Intact adult	1.4
Inactive or gains weight easily	1.0
Kitten	2.5
Weight loss (at ideal weight, with your vet)	0.8

A 10 lb cat weighs 4.5 kg. 4.5 to the power 0.75 is about 3.1, times 70 gives an RER of about 218 kcal. For a neutered adult, 218 × 1.2 ≈ 260 kcal a day.

Cats vary. Two cats of the same weight can differ by 20–30%, so use this as a starting point and adjust by what the scale says. The cat calorie calculator shows each step for your own cat.

Where do I find calories on the can?

US pet food labels list a calorie content statement, usually near the guaranteed analysis. For wet food, look for “kcal per can” (or per pouch). For dry food, look for “kcal per cup” and “kcal/kg”.

Calories vary a lot. Small 3 oz cans often have somewhere around 70–110 kcal, and 5.5 oz cans often 140–200 kcal, but pâtés, chunks in gravy and “light” recipes all differ. Always use the number on your label.

How much wet food should I feed my cat by weight?

This chart assumes a neutered adult (1.2 × RER) and an all-wet diet. It shows two common can sizes.

Cat’s weight	Calories per day	3 oz cans (90 kcal)	5.5 oz cans (170 kcal)
6 lb	~180	~2	~1
8 lb	~220	~2½	~1¼
10 lb	~260	~3	~1½
12 lb	~300	~3⅓	~1¾
14 lb	~335	~3¾	~2

If your cat is overweight, don’t use the current weight. Feed for the ideal weight, and talk to your vet first (more on that below).

How do I split wet and dry food?

Split the calories, then convert each part. Here’s the 10 lb cat at 260 kcal on a 50/50 split:

1. Wet share: 50% of 260 = 130 kcal. With a 90 kcal can, that’s 130 ÷ 90 ≈ 1½ cans.
2. Dry share: the other 130 kcal. With a 400 kcal/cup kibble, that’s 130 ÷ 400 ≈ ⅓ cup (just under ⅜ cup).
3. Or in grams: a kibble with 3,800 kcal/kg has 3.8 kcal per gram, so 130 ÷ 3.8 ≈ 34 g of dry.

Other splits for the same cat:

Split (wet/dry)	Wet (90 kcal cans)	Dry (400 kcal/cup)
100/0	~3 cans	none
75/25	~2¼ cans	~⅛ cup
50/50	~1½ cans	~⅓ cup
25/75	~¾ can	~½ cup
0/100	none	~⅝ cup

That last row surprises people: an all-dry diet for a 10 lb cat is only about ⅝ cup a day. Dry food is dense. A heaped scoop can be a whole day’s calories. A kitchen scale makes this much easier to get right. The cat food calculator works any split out for you.

Is wet or dry food better for cats?

Both can be complete and balanced. The differences are practical:

	Wet food	Dry food
Water content	About 60–87%	About 3–11%
Calories per bite	Lower	Much higher
Cost per day	Higher	Lower
Can sit out	Short time only	All day (but that encourages overeating)
Good for	Extra water, weight control, picky eaters	Convenience, puzzle feeders, budget

Cats evolved to get much of their water from prey, and many don’t drink much from a bowl. Wet food is an easy way to get more water into them, which vets often suggest for cats prone to urinary problems. Your vet can tell you whether that matters for your cat.

Many owners use both: wet meals morning and evening, plus a measured amount of dry in a puzzle feeder during the day.

How often should I feed my cat?

Most adult cats do well on at least two meals a day. Some prefer several small meals, which you can do by dividing the day’s portion. Kittens need three or four meals.

Wet food shouldn’t sit out for long. A common guideline is to pick it up after about 20–30 minutes, sooner in warm weather. Cover and refrigerate opened cans.

How much wet food should a kitten eat?

Kittens grow fast and need about 2.5 × RER. A 4 lb kitten (1.8 kg) has an RER of about 110 kcal, so it needs roughly 275 kcal a day, about as much as a 10 lb adult. Feed a food labeled for growth (or “all life stages”), in three or four meals, and weigh your kitten every couple of weeks. Most cats move to adult food around their first birthday.

What if my cat needs to lose weight?

Overweight cats are common, and extra weight raises the risk of diabetes and joint problems. But cats need to lose weight slowly. A cat that suddenly eats very little, especially an overweight cat, can develop a serious liver condition called hepatic lipidosis. So:

• Talk to your vet before starting a diet.
• Aim for slow loss, often around 0.5–2% of body weight a week.
• Feed for the ideal weight, not the current one. Vets often start near 0.8 × RER at the ideal weight.
• Swap some dry food for wet: it fills the bowl with fewer calories.
• Weigh every two to four weeks and adjust.

When should I call my vet?

Call your vet if your cat:

• stops eating for more than a day, or eats much less than usual,
• loses or gains weight without a change in food,
• drinks or urinates a lot more than before,
• vomits often, or has diarrhea that lasts more than a day or two,
• has a medical condition or eats a prescription diet.

For a healthy cat, this guide and the calculator give you a solid starting portion. Your cat’s weight and body shape over the next few weeks will tell you whether to adjust.