How Many Grams of Cat Food a Day? After Neutering, for Kittens and for Senior Cats

Calculate a cat's food from calories

A cat's calorie needs are calculated with the same formula as a dog's. The difference is the factor. Cats are naturally less active than dogs, and a spayed or neutered indoor cat's factor of 1.2 is well below a dog's (1.6).

1. 1

   Find the RER

   RER = 70 × (weight in kg)^0.75. For 4 kg, that's about 198 kcal.

2. 2

   Apply a factor to get daily calories

   For a spayed or neutered adult cat, × 1.2 gives about 238 kcal. For an intact cat, × 1.4 gives about 277 kcal.

3. 3

   Convert to grams using the food's calories

   For dry food at 380 kcal per 100 g, 238 ÷ 380 × 100 ≈ 63 g. If 10% goes to treats, it's about 56 g.

A 4 kg cat needs about 238 kcal a day, around 1/8 to 1/10 of an adult human. Considering their size, a difference of a few tablespoons of dry food has a big effect on weight. Measuring on a kitchen scale is recommended.

Chart of a cat's daily calories by weight

Here are calories by adult cat weight, and grams calculated for dry food at 380 kcal per 100 g.

Cut about 15% after spaying or neutering

After spaying or neutering, hormonal changes reduce calorie needs while appetite tends to rise. "My cat suddenly got fat after surgery" is a common story, and continuing the pre-surgery amount is the top cause.

• The factor goes from 1.4 to 1.2, so calories needed fall by about 14% (roughly 15%).
• If surgery happens while still growing (under 1 year), don't cut suddenly from the growth factor; review it when switching to adult food.
• If the reduced amount doesn't seem enough, more meals with less in each shorten the hungry stretches.
• Food for spayed or neutered cats is often lower in calories, so recalculate the grams after switching.

Amounts for kittens and senior cats

Kittens grow fastest up to 4 months, with a factor of 3.0. From 4 months to 1 year, calculate with 2.0–2.5. They need 2–2.5 times an adult's calories, so use kitten food and split it into 3–4 meals a day.

Kittens grow with what they eat, so there's rarely a need to restrict them for fear of overeating. Weigh weekly; steady gains are enough. When growth settles at around 1 year, switch to adult food and an adult factor (1.2 if spayed or neutered).

Senior cats move less at around 7–11 years, so lower the factor to 1.1. For a spayed or neutered 5 kg cat, that's a cut of about 10%, from 281 kcal to 257 kcal. After 11, however, digestion and absorption weaken and more cats grow thin. If weight falls, raise the factor to 1.2–1.4, and consult a veterinarian about sudden weight loss, which may signal illness.

How many pouches if feeding only wet food

Wet food (cans and pouches) is about 80% water, at around 85 kcal per 100 g, about 1/4 of dry food's calories. So meeting calorie needs with wet food alone takes quite a lot.

• A spayed or neutered 4 kg cat (about 238 kcal a day, about 214 kcal after 10% for treats) needs about 252 g of wet food at 85 kcal/100 g, or about 3.6 pouches of 70 g.
• Use only products labeled complete and balanced as the main diet. Products labeled general food, supplemental food or side dishes don't provide enough nutrition alone.
• Opened wet food spoils easily, so clear away leftovers and warm refrigerated food to skin temperature before serving.

Calculations for combining dry and wet food, and water amounts that account for wet food's moisture, are covered in detail in Mixing Dry and Wet Food, and How Much Water.

End free feeding: set the amount and split the meals

Cats naturally eat small amounts many times a day, so many homes leave food out all day. But with free feeding, you can't tell how many grams were eaten in a day, and overeating can creep up on you.

1. 1

   Weigh the day's amount in the morning

   Weigh out the calculated daily amount in the morning and put it in a container. Serve only from that for the day to prevent overeating.

2. 2

   Give it in 3–4 meals

   Smaller, more frequent meals are closer to how cats eat and reduce hungry meowing. An automatic feeder is another option.

3. 3

   Weigh every 2–4 weeks

   Hold your cat, step on the scale together and subtract your own weight. Reduce by 5–10% if weight has gone up, and increase by 5–10% if it has gone down.

Calculate your cat's amount with the tool

In the Dog & Cat Food Portion Calculator, choose cat, then weight, BCS and lifestyle (kitten, spayed/neutered, senior, weight loss and so on) to get daily calories and grams of food right away. Enter the bag's kcal/100 g or kcal/kg and choose meals per day to see the amount per meal. The "Chart by weight" tab lists calories by factor for weights from 1 to 10 kg. A list of foods cats must never have is also in the tool.

FAQ

How many grams of food should a 4 kg cat eat a day?

A spayed or neutered adult cat needs about 238 kcal a day, or about 63 g of dry food at 380 kcal per 100 g. With 10% of the day as treats, food is about 56 g. An intact cat needs about 277 kcal (about 73 g).

How much should I cut after spaying or neutering?

The factor goes from 1.4 to 1.2, so calories needed fall by about 15%. For a 4 kg cat, go from about 277 kcal to about 238 kcal, or from about 73 g to about 63 g of dry food at 380 kcal/100 g.

How much should I feed a kitten?

RER × 3.0 up to 4 months, and × 2.0–2.5 from 4 months to 1 year, is the guide. A 3-month-old, 1.5 kg kitten needs about 285 kcal a day, or about 71 g of kitten food at 400 kcal/100 g, split into 3–4 meals.

How many pouches a day when feeding only wet food?

For a spayed or neutered 4 kg cat, with wet food at 85 kcal/100 g, about 252 g a day, or about 3.6 pouches of 70 g (after subtracting 10% for treats). For a main diet, choose products labeled complete and balanced.

Should I reduce food for a senior cat?

If activity has fallen at around 7–11 years, lowering the factor from 1.2 to 1.1, a cut of about 10%, is the guide. If your cat grows thin after 11, raise it to 1.2–1.4 instead. Consult a veterinarian about sudden weight loss.