How Much Does Your Pet Eat?

Here’s A Handy Formula

The rule of thumb for how much food your pet will eat in a month is:

1/2 its body weight


  • A 20 pound dog = 10 pounds of food each month. And 120 pounds in a year.
  • A 10 pound cat = 5 pounds of food each month. And 60 pounds in a year.
  • If you are lucky and have a 120 pound Newfie, he will eat 60 pounds of food in a month. That’s a whopping 720 pounds of food in a year.

Keep in mind, this is simply an estimation. It is based on a healthy pet with no special conditions (e.g., this doesn’t apply to kittens, puppies, pregnant animals, etc.). Interestingly, the same rule applies to both cats and dogs.

Why Might This Be Useful?

dog covered in treats

  • Tracking how much you really are feeding your pet.
  • Keeping a pet-related budget.
  • Scheduling auto-shipments of pet food each month.
  • Dazzle friends and co-workers with seemingly random trivia.

How Much Food Per Day?

The answer here depends on pet calorie needs per day, what food you are feeding, their body conditioning score (BCS), and how active they are. We bet you’ll be surprised at how seemingly few calories per day they need and what little food that represents.

fat cat in pet door

Step One: Pet Calorie Needs

How many calories does your pet need per day? This will vary on breed, overall size and health, activity level and whether they are spayed or neutered.

  • The Pet Nutritional Alliance has a handy pet calorie calculator for both dogs and cats. Give it a try!
  • Dr. Ernie Ward is well-known for his quest to prevent pet obesity. His website has great resources for finding ideal weights, calories, and how fast those treats add up!

Step Two: Calories in the Food

Carefully read the bag of food for nutritional information. You will want to find how many calories are in one cup of food. If you can’t find this in the microscopic print on the back of the bag (or sides), try checking the company website. Many companies list detailed information online (and in readable print).

Step Three: Body Conditioning Score

If you look straight down at your pet while he is standing, is he long and lean? Or does he look like a football? If you look at your pet from the side, does the abdomen tuck up slightly or sag and bag towards the floor?

Editor’s note: Getting 3 cats (who truly have differing body shapes) to stand still and pose was surprisingly difficult. While the middle “healthy body” cat appears huge, he is a Maine Coon so he is more fluff than fat.

Even though they happen to be lying down, these pictures are a better indicator of the overall physical difference in the two cats.

The Ohio State University has a great visual guide to Body Conditioning Scores for both cats and dogs. (They cheated and drew sketches of the pets.)

Real Life Example

The lean body cat (Scooby) is 9.6 pounds. He is a 1.5 year old neutered male and playful. He is a great weight, but definitely lean. According to the Pet Nutrition Alliance calorie calculator, his pet calorie needs are about 200-234 calories per day.

The overweight body (Daphne who thankfully can’t read) is 11.2 pounds.  She is a 5 year old spayed female who loves her naps. She is overweight, but not obese. They calculate her calories around 158 a day (in order to slowly reduce her weight to around 9 pounds).

They eat Natural Balance Wild Pursuits Trout Formula. According to the bag (and website), for a ten pound cat, that would be only 3/4 of a cup of food per day. But, one cup of this food has 365 calories/cup. In reality, they would only need 1/2 cup, maybe 2/3 cup of food per day! Makes your diet look fabulous, doesn’t it!

Get checking those food facts and keep your pets healthy and active for the long haul!