How Much to Feed My Dog: Use the Calories on the Bag

The short answer

Feed your dog its daily calorie need divided by the calories in its food. The calories are printed on the bag under “Calorie Content.” The daily need comes from a standard veterinary formula based on weight and life stage. For a typical neutered 40 lb adult dog that works out to about 860 to 990 calories a day. On a food with 400 calories per cup, that’s a little over 2 to just under 2½ cups.

That number is a starting point, not a prescription. Weigh your dog every couple of weeks and adjust. The dog and cat calorie calculator does the arithmetic below for any weight and food.

Start with the calorie statement, not the feeding chart

Every complete dog food sold in the US has two things on the bag that matter here.

The feeding directions. This is usually a table of “cups per day” by body weight. WSAVA’s label guide says it must at least state an amount per weight of dog and how often to feed.

The calorie content statement. This is the one to use. According to WSAVA’s label guide, it is mandatory and must give calories at least two ways: kcal per kilogram and kcal per familiar household measure, such as per cup or per can. The heading reads “calorie content (fed)” if the maker measured it in feeding trials, or “calorie content (calculated)” if it was estimated from the protein, fat and carbohydrate.

WSAVA calls label feeding amounts “a good starting point” built for the “average” dog at a given weight. It also says individual dogs can vary up to 50% above or below those starting points. A chart that covers “40–60 lb” in one row can’t tell an active intact 55 lb dog from a neutered couch-lover of the same weight. The calorie statement lets you do that yourself.

The formula vets use

The 2021 AAHA Nutrition and Weight Management Guidelines use two steps.

1. Resting energy requirement (RER): the calories your dog burns at rest.

RER = 70 × (body weight in kg)^0.75

2. Maintenance energy requirement (MER): what your dog needs in a normal day.

MER = RER × a life-stage factor

To convert pounds to kilograms, multiply by 0.4536. To raise a number to the 0.75 power on a phone, turn the calculator sideways and use the x^y key. AAHA’s own handout gives those same steps.

These are the dog factors from AAHA’s Box 1 that the calculator uses:

Your dog	Factor × RER
Neutered or spayed adult	1.4–1.6
Intact adult	1.6–1.8
Inactive or gains weight easily	1.0–1.2
Weight loss (use target weight)	1.0
Puppy under 4 months	3.0
Puppy 4 months to adult size	2.0
Light work	1.6–2.0

AAHA adds two notes worth taking seriously. Sedentary or indoor pets may need fewer calories than the table suggests. And intake should be adjusted by watching body weight and body condition score. The factors give you a range for a reason.

Worked example: a 55 lb intact adult

Say your dog weighs 55 lb, is not neutered, and is a healthy adult. The bag says:

Calorie content (calculated): 3,600 kcal/kg; 400 kcal/cup

Weight in kg: 55 × 0.4536 = 24.95 kg

RER: 24.95^0.75 = 11.16, and 70 × 11.16 = 781 kcal

MER at the intact-adult factor of 1.6 to 1.8: 781 × 1.6 = 1,250 kcal and 781 × 1.8 = 1,407 kcal a day

In cups: 1,250 ÷ 400 = 3.13 cups, up to 1,407 ÷ 400 = 3.52 cups. So about 3⅛ to 3½ cups a day.

In grams: 3,600 kcal/kg is 3.6 kcal per gram. 1,250 ÷ 3.6 = 347 g, up to 1,407 ÷ 3.6 = 391 g. So about 350 to 390 g a day.

If your dog gets treats: WSAVA advises keeping treats to about 10% of daily calories. At the top of the range that’s a budget of about 141 kcal. Setting 10% aside brings the food down to about 2.8 to 3.2 cups, or 313 to 352 g.

Start in the middle, around 3¼ cups with no treats or 3 cups with treats. Then let the scale tell you which way to move.

If this dog is neutered later, the factor drops to 1.4–1.6, or about 1,094 to 1,250 kcal. On the same food that’s roughly 2¾ to 3⅛ cups. Neutering is one of the most common times for a dog’s needs to change, so re-check the amount afterward.

Quick reference: neutered adults by weight

These are RER and MER (factor 1.4–1.6) worked out with the same formula and rounded to the nearest calorie. The last column uses the “inactive” factor (1.0–1.2) for comparison.

Dog’s weight	RER (kcal/day)	Neutered adult MER	Inactive dog
10 lb (4.5 kg)	218	305–348	218–261
20 lb (9.1 kg)	366	512–585	366–439
40 lb (18.1 kg)	615	862–985	615–738
60 lb (27.2 kg)	834	1,168–1,335	834–1,001
80 lb (36.3 kg)	1,035	1,449–1,656	1,035–1,242

Divide by your food’s kcal per cup to get cups. A 20 lb neutered dog on a 350 kcal/cup food needs about 1.5 to 1.7 cups (512 ÷ 350 and 585 ÷ 350).

Notice that calories don’t double when weight doubles. An 80 lb dog needs about 2.8 times the calories of a 20 lb dog, not 4 times, because of the 0.75 exponent. That’s one reason a straight “cups per 10 lb” rule overfeeds big dogs.

Measuring: cup, scoop or scale

The label’s “per cup” figure means a standard 8 fl oz measuring cup, leveled off. A free scoop, a coffee mug or a heaped cup can hold noticeably more. Over weeks, that difference shows up on the scale.

The most accurate option is a cheap kitchen scale and the kcal/kg figure. Weigh the day’s food in grams, split it into meals, and you remove the guesswork from cup size and kibble shape.

How to tell if the amount is right

The formula gets you close. Your dog’s body tells you the rest.

• Weigh regularly. WSAVA suggests adjusting the amount every 2 weeks at first. Once weight holds steady, check monthly.
• Check body condition. WSAVA uses a 9-point body condition score, where 4 to 5 out of 9 is ideal. Below 4 is underweight and above 5 is overweight. Its dog body condition chart shows what each score looks and feels like. At a 5, the ribs can be felt without excess fat over them and a waist shows behind the ribs when you look from above.
• Adjust in small steps. If the dog is gaining, move toward the low end of the range. If it’s losing weight it shouldn’t, move toward the high end. Then weigh again in 2 weeks.

Common mistakes

• Using the feeding chart as gospel. WSAVA itself says individual dogs can differ by up to 50% from it.
• Forgetting treats, chews and table scraps. They count. Keep them to about 10% of the day’s calories.
• Using current weight for an overweight dog. For weight loss, AAHA’s factor is applied to the target weight, and the plan should come from your vet.
• Comparing foods by cups. Calories per cup vary from food to food. Switching brands without re-checking the calorie statement can quietly add or cut a lot.
• Measuring with a scoop of unknown size. Level a real measuring cup or, better, weigh it.
• Not re-checking after life changes. Neutering, a move to less exercise, and aging all change calorie needs.

When to ask your vet

Use the formula for a healthy adult. Talk to your vet before relying on it, or as soon as you notice a problem, if:

• Your dog is a puppy. AAHA’s growth factors are 2 to 3 times RER, and needs change month by month. Your vet can set a growth plan.
• Your dog is pregnant or nursing. AAHA’s factors here climb as high as 6 times RER depending on the stage and litter size, too wide to guess at. The calculator leaves them out on purpose.
• Your dog needs to lose a lot of weight. A vet-guided plan sets the target weight and how fast to lose it.
• Your dog is on a prescription or therapeutic diet. Follow the vet’s amount, not a general formula.
• Weight changes without a diet change. Unexplained weight loss or gain, a sudden change in appetite, or drinking much more than usual are reasons for an exam, not just a new feeding amount.

Putting it together

Find “Calorie Content” on the bag. Work out the range with RER and the right factor, or let the calorie calculator do it. Then feed toward the middle, weigh, and adjust. If you’re budgeting for food alongside everything else, the pet cost calculator puts it in a yearly total.

This estimate uses published veterinary formulas. Every dog is different. Use it as a starting point and check with your veterinarian, especially for puppies, pregnant or nursing dogs, or dogs with a health condition.