How Many Calories Does a Cat Need a Day? Wet, Dry and Weight Loss

A typical indoor cat should eat far fewer calories per day than most people guess: about 261 kcal a day for a neutered 10 lb adult, and about 318 kcal for a 13 lb cat. That is roughly 3.1 small cans of wet food, or about two thirds of a cup of a typical kibble, for the 10 lb cat. To calculate calories for your own cat, convert its weight to kilograms, work out 70 × kg^0.75, and multiply by 1.2 for a neutered indoor adult. Most overweight cats got there on portions that looked reasonable, which is why the number is worth working out rather than eyeballing.

The calculation every cat calorie calculator runs has two steps. Once you can see them, you can check any feeding guide on a bag against your own cat.

Step one: the resting energy requirement

RER is what a cat burns lying still. The standard veterinary formula is 70 × (body weight in kg)^0.75, the same one used for dogs. The 0.75 exponent is the important part: calorie needs grow more slowly than body weight. A 20 lb cat weighs a bit over three times what a 6 lb cat does and needs about 2.5 times the calories at rest.

Step two: the life-stage multiplier

The maintenance energy requirement, MER, is RER multiplied by a factor for life stage and neuter status. Cat factors are much lower than dog factors, because the typical house cat is sedentary and most are neutered. Here is what each factor means for a 10 lb cat:

Life stage	Factor	kcal/day at 10 lb
Kitten (growth)	×2.5	544
Adult, neutered	×1.2	261
Adult, intact	×1.4	305
Senior	×1.15	250
Weight loss	×0.8	174

The neutered-adult row is the one most owners need. Neutering reduces energy needs noticeably, and the most common mistake is keeping a cat on its pre-surgery portion. Kittens are the opposite case, at ×2.5, and they have their own guide: how much to feed a kitten, with meals per day by age.

Daily calories by weight

Neutered adults at ×1.2. Cups assume a 400 kcal/cup dry food; grams assume 3800 kcal/kg; small cans are 85 kcal each.

Weight	RER	Neutered	Intact	Senior	Dry cups	Dry grams	3 oz cans
6 lb	148	178	208	171	0.45	47	2.1
8 lb	184	221	258	212	0.55	58	2.6
10 lb	218	261	305	250	0.65	69	3.1
12 lb	249	299	349	287	0.75	79	3.5
13 lb	265	318	371	305	0.8	84	3.7
15 lb	295	354	413	339	0.89	93	4.2
20 lb	366	439	512	421	1.1	116	5.2

The 15 and 20 lb rows are for genuinely large cats, such as a Maine Coon or a Ragdoll at a healthy weight. A domestic shorthair that weighs 15 lb is usually an overweight 10 or 11 lb cat, and should be fed for the lower number.

Wet food, dry food, or both

Calories are the stable number. The amount of food that delivers them depends entirely on the product. Dry cat foods commonly run 350 to 500 kcal per cup. Wet foods are mostly water, so they carry far fewer calories per ounce: a 3 oz can is often 70 to 100 kcal and a 5.5 oz can 140 to 200, with pâtés at the high end and chunks in gravy at the low end. The label will state kcal per can or per kilogram; use that, not the feeding chart, which is usually written for an active, intact cat.

Mixed feeding is where the arithmetic matters most, because it is easy to feed a full ration of each. Worked example for a 10 lb neutered cat at 261 kcal: one 5.5 oz can at 170 kcal covers most of the day, leaving 91 kcal, which is about 0.23 cups of a 400 kcal/cup kibble. That is roughly a quarter cup, not the half cup that often ends up in the bowl alongside the can.

Wet food has real advantages for many cats. The water content helps cats that drink little, which matters for urinary health, and the lower energy density makes it easier to feel full on fewer calories. Dry food is cheaper and convenient. Either can be complete and balanced; look for a nutritional adequacy statement for adult maintenance on the label.

How this compares to other formulas

Not every tool uses the same equation. Some clinics use a linear shortcut, 30 × kg + 70, which gives 206 kcal of resting energy for a 10 lb cat against 218 from the exponential formula. The National Research Council's 2006 nutrient requirements give separate equations for lean and overweight cats: 100 × kg^0.67 for lean cats (275 kcal for 10 lb) and 130 × kg^0.4 for overweight ones (238 kcal). Those are total daily figures, so compare them with the 261 kcal MER, not the RER.

The spread between methods is real but modest, around 10 to 15 percent. The bigger errors come from the inputs: using the wrong life stage, feeding for an overweight cat's current weight, and forgetting treats.

Feeding an overweight cat down

Feed for the target weight, not the current one. Say your cat weighs 14 lb and your vet thinks 11 lb is right. Feeding the 14 lb cat as a normal neutered adult means 336 kcal a day, which maintains the extra weight. The weight-loss factor of ×0.8 applied to the 11 lb target gives 187 kcal a day.

Go slowly. Aim for about 1 percent of body weight a week, about 0.14 lb for this cat, which means roughly 21 weeks to reach the target. That feels slow, and it should. Cats that are starved, or that refuse a new diet and stop eating, can develop hepatic lipidosis, a fatty liver condition that can kill them. A vet should supervise any real weight-loss plan, and a cat that stops eating for more than a day or two needs to be seen.

Treats count. Keep them under about 10 percent of daily calories, which is around 26 kcal for a 10 lb cat. A few commercial treats can be 2 to 3 kcal each, a lick of cheese or butter far more.

Check the cat, not the calculator

Every formula here is a starting point. Individual cats of the same weight can differ by 20 percent or more. Feed the number for three or four weeks, weigh the cat on the same scale each time, and check body condition. On the 9-point scale vets use, 5 is ideal: ribs easy to feel under a light layer of fat, a visible waist behind the ribs from above, and only a small belly pouch. If the cat is gaining, cut 10 percent; if it is losing and should not be, add 10 percent.

To run your own cat's numbers, use the pet calorie calculator and pick Cat, then the life stage and the kcal on your food's label. The dog version of this guide covers the same formula with dog multipliers, and the cat age calculator shows where your cat sits on the senior curve, which is when the lower senior factor starts to apply. If you have more than one cat, the litter box guide covers the other thing multi-cat homes usually get wrong.