How many grams of dry food should a cat eat a day?

Daily calories divided by the kcal/kg on the bag, times 1,000. Indoor cats: 53 g at 3 kg, 60 g at 4 kg, 65 g at 5 kg, 70 g at 6 kg on a 3,800 kcal/kg food. That is far less than a full bowl, so weigh it.

How many grams in half a cup or a quarter cup of dry cat food?

On the same five labels, half a cup is 46-57 g, a third of a cup 31-38 g and a quarter cup 23-28 g. With a 100 g cup: 50, 33 and 25 g.

How many cups is that?

The 4 kg indoor cat's 60 g a day is 1/2 to 5/8 cup on those labels, or 0.60 of a 100 g cup. Cup weights differ by 23% between the five foods, so weigh one level cup of your own food on a kitchen scale and feed by grams. The cat food calculator takes kcal per cup when the bag prints it.

Does an active cat get more?

A lean, active 4 kg cat is on the NRC lean equation (100 x kg^0.67): 67 g a day of the same 3,800 kcal/kg food against 60 g for an indoor one. Use the lean table for outdoor cats with a visible waist.

How long does a 2 kg bag last?

For the 4 kg indoor cat at 60 g a day: 34 days. A 7.5 kg bag lasts 126 days, a long time for an open bag of kibble; buy a size you will finish while it is fresh.

Dry only, or mixed with wet?

Either works if the calories add up. Wet food adds water, which many vets prefer for cats prone to urinary problems; the wet food guide gives pouches for a half-and-half split. Free feeding kibble is the most common route to an overweight cat: measure the daily amount once and split it.

How much dry food to feed a cat per day? Grams by weight

An indoor, neutered 4 kg (8.8 lb) cat needs about 226 kcal a day, which is 60 g of a 3,800 kcal/kg kibble: 30 g per meal, twice a day. A level 8 oz measuring cup holds 92 to 113 g of dry cat food on five US labels, so that is 1/2 to 5/8 cup a day. On a lighter 3,500 kcal/kg food it is 65 g, on a dense 4,400 kcal/kg food 51 g. The tables give grams and cups a day for 3 to 6 kg cats, indoor and active, and how long a bag lasts.

Open the cat food calculator

How many grams in a cup of dry cat food?

92 to 113 g in a level 8 oz measuring cup, on five US dry cat foods; the cat food calculator's default label (380 kcal per cup, 3,800 kcal/kg) works out at 100 g. The weight depends on the size and density of the kibble, which is why the heaviest cup below is 23% heavier than the lightest. US bags print the two figures you need: grams per cup = kcal per cup / kcal per kg x 1,000.

Grams in one level cup, from the calorie statement on five dry cat foods
Food	kcal/kg	kcal per cup	Grams per cup
Hill's Science Diet Adult Indoor Chicken Recipe	3,492	327	94 g (3.3 oz)
Royal Canin Indoor Adult	3,534	325	92 g (3.2 oz)
Purina Cat Chow Complete	3,688	411	111 g (3.9 oz)
Purina ONE Indoor Advantage Adult	3,756	372	99 g (3.5 oz)
Purina Pro Plan Complete Essentials Adult Chicken & Rice	4,358	494	113 g (4.0 oz)

Label figures as published by the makers, read 2026-10-01; recipes change, so the numbers on your bag win. Two of the labels also state the cup weight (Purina ONE about 99 g, Pro Plan about 113 g) and Hill's prints 3.3 oz by weight; all three match the calculation within 1 g.

Grams in half, a third or a quarter cup of dry cat food

Grams in part of a level 8 oz cup, lightest label, calculator default and heaviest label
Amount	92 g cup	100 g cup	113 g cup
1/8 cup	11 g	13 g	14 g
1/4 cup	23 g	25 g	28 g
1/3 cup	31 g	33 g	38 g
1/2 cup	46 g	50 g	57 g
2/3 cup	61 g	67 g	76 g
3/4 cup	69 g	75 g	85 g
1 cup	92 g	100 g	113 g

Cups of dry food a day by cat weight

Indoor or neutered cat (NRC 2006, 130 x kg^0.4): daily kcal divided by the kcal per cup on the bag. The columns are the lowest kcal per cup of the five labels (325), the calculator's default (380) and the highest (494); the nearest eighth of a cup is in brackets.

Level cups of dry food per day for an indoor cat, by kcal per cup
Cat weight	kcal/day	325 kcal/cup	380 kcal/cup	494 kcal/cup
3 kg (6.6 lb)	202	0.62 (5/8)	0.53 (1/2)	0.41 (3/8)
3.5 kg (7.7 lb)	215	0.66 (5/8)	0.56 (5/8)	0.43 (3/8)
4 kg (8.8 lb)	226	0.70 (3/4)	0.60 (5/8)	0.46 (1/2)
4.5 kg (9.9 lb)	237	0.73 (3/4)	0.62 (5/8)	0.48 (1/2)
5 kg (11 lb)	247	0.76 (3/4)	0.65 (5/8)	0.50 (1/2)
5.5 kg (12.1 lb)	257	0.79 (3/4)	0.68 (5/8)	0.52 (1/2)
6 kg (13.2 lb)	266	0.82 (7/8)	0.70 (3/4)	0.54 (1/2)

Indoor or neutered cat, dry food only

Grams a day on the NRC 2006 obese-prone equation (130 x kg^0.4), for kibble labelled 3,500 to 4,400 kcal per kg (the five labels above run from 3,492 to 4,358). Split into two or more meals.

Grams of dry food per day for an indoor cat, by weight and kcal/kg
Cat weight	kcal/day	3,500 kcal/kg	3,800 kcal/kg	4,100 kcal/kg	4,400 kcal/kg
3 kg (6.6 lb)	202	58 g	53 g	49 g	46 g
3.5 kg (7.7 lb)	215	61 g	56 g	52 g	49 g
4 kg (8.8 lb)	226	65 g	60 g	55 g	51 g
4.5 kg (9.9 lb)	237	68 g	62 g	58 g	54 g
5 kg (11 lb)	247	71 g	65 g	60 g	56 g
5.5 kg (12.1 lb)	257	73 g	68 g	63 g	58 g
6 kg (13.2 lb)	266	76 g	70 g	65 g	60 g

Lean, active cat

The NRC lean-adult equation (100 x kg^0.67), same label columns.

Grams of dry food per day for a lean, active cat
Cat weight	kcal/day	3,500 kcal/kg	3,800 kcal/kg	4,100 kcal/kg	4,400 kcal/kg
3 kg (6.6 lb)	209	60 g	55 g	51 g	47 g
3.5 kg (7.7 lb)	231	66 g	61 g	56 g	53 g
4 kg (8.8 lb)	253	72 g	67 g	62 g	58 g
4.5 kg (9.9 lb)	274	78 g	72 g	67 g	62 g
5 kg (11 lb)	294	84 g	77 g	72 g	67 g
5.5 kg (12.1 lb)	313	90 g	82 g	76 g	71 g
6 kg (13.2 lb)	332	95 g	87 g	81 g	75 g

How long a bag lasts

Indoor cat on a 3,800 kcal/kg food; divide the bag weight by the daily grams.

Days per bag by cat weight and bag size
Cat and daily amount	1.5 kg bag	2 kg bag	4 kg bag	7.5 kg bag
3 kg cat, 53 g/day	28 days	38 days	75 days	141 days
4 kg cat, 60 g/day	25 days	34 days	67 days	126 days
5 kg cat, 65 g/day	23 days	31 days	61 days	115 days
6 kg cat, 70 g/day	21 days	29 days	57 days	107 days

Reading the label

US bags print kcal per cup and per kg; EU bags print kcal or kJ per 100 g, so multiply by ten for kcal/kg (divide kJ by 4.184 first). The cat food calculator takes either figure and any wet share; the cost calculator turns the grams into a monthly bill. For the wet share in grams, see how much wet food to feed a cat in grams. Cats vary by up to 30%: re-weigh after two weeks and keep the ribs easy to feel under a thin cover. For dog kibble, see how many calories are in a cup of dog food; for kittens, how much to feed a kitten.

Frequently asked questions

How many grams of dry food should a cat eat a day?: Daily calories divided by the kcal/kg on the bag, times 1,000. Indoor cats: 53 g at 3 kg, 60 g at 4 kg, 65 g at 5 kg, 70 g at 6 kg on a 3,800 kcal/kg food. That is far less than a full bowl, so weigh it.
How many grams in a cup of dry cat food?: 92 to 113 g in a level 8 oz measuring cup across five US cat food labels, and 100 g on the cat food calculator's default label (380 kcal per cup, 3,800 kcal/kg). For your own bag, divide the kcal per cup by the kcal per kg and multiply by 1,000: 372 kcal per cup on a 3,756 kcal/kg food is 99 g.
How many grams in half a cup or a quarter cup of dry cat food?: On the same five labels, half a cup is 46-57 g, a third of a cup 31-38 g and a quarter cup 23-28 g. With a 100 g cup: 50, 33 and 25 g.
How many cups is that?: The 4 kg indoor cat's 60 g a day is 1/2 to 5/8 cup on those labels, or 0.60 of a 100 g cup. Cup weights differ by 23% between the five foods, so weigh one level cup of your own food on a kitchen scale and feed by grams. The cat food calculator takes kcal per cup when the bag prints it.
Does an active cat get more?: A lean, active 4 kg cat is on the NRC lean equation (100 x kg^0.67): 67 g a day of the same 3,800 kcal/kg food against 60 g for an indoor one. Use the lean table for outdoor cats with a visible waist.
How long does a 2 kg bag last?: For the 4 kg indoor cat at 60 g a day: 34 days. A 7.5 kg bag lasts 126 days, a long time for an open bag of kibble; buy a size you will finish while it is fresh.
Dry only, or mixed with wet?: Either works if the calories add up. Wet food adds water, which many vets prefer for cats prone to urinary problems; the wet food guide gives pouches for a half-and-half split. Free feeding kibble is the most common route to an overweight cat: measure the daily amount once and split it.

How much wet food to feed a cat per day?
Pouches and cans a day for cats from 3 to 6 kg, wet only or half wet, half dry, for pouches labelled 70 to 110 kcal, plus the grams of kibble to add.
How many calories does a kitten need? How much to feed a kitten by age and weight
A 12-week, 1.2 kg kitten needs about 214 kcal a day (178 kcal per kg, NRC 2006). Calories by age in weeks and months, per kg and per lb, pouches and cups.
How many calories does a cat need per day?
Calories a day for cats from 2 to 8 kg: resting requirement, indoor and neutered, lean and active, the WSAVA chart range and the weight-loss target.
How many calories should a cat eat to lose weight?
Diet calories by target weight (resting requirement of the ideal weight, AAHA 2021), grams and pouches a day, and how many weeks a safe plan takes at 0.5-2% a week.

Sources

NRC 2006, Nutrient Requirements of Dogs and Cats — adult, puppy and kitten energy equations
WSAVA, Calorie Needs for Healthy Adult Dogs (July 2020) — chart range for dogs
WSAVA, Calorie Needs for Healthy Adult Cats (July 2020) — chart range for cats
AAHA 2021 Nutrition and Weight Management Guidelines — weight loss at the resting requirement of the target weight
Hill's Science Diet Adult Indoor Chicken Recipe, calorie content — 3,492 kcal/kg, 327 kcal per cup, read 2026-10-01
Royal Canin Indoor Adult, calorie content — 3,534 kcal/kg, 325 kcal per cup, read 2026-10-01
Purina Cat Chow Complete, calorie content — 3,688 kcal/kg, 411 kcal per cup, read 2026-10-01
Purina ONE Indoor Advantage Adult, calorie content — 3,756 kcal/kg, 372 kcal per cup, read 2026-10-01
Purina Pro Plan Complete Essentials Adult Chicken & Rice, calorie content — 4,358 kcal/kg, 494 kcal per cup, read 2026-10-01

Published 2026-09-17, last updated 2026-10-03. Figures are starting points from the published equations: individual animals vary by up to 30%, so adjust by body condition and ask your vet for puppies under 8 weeks, pregnancy, lactation or any illness.