How much to feed a puppy, by age and weight

The rule the guidelines use

The 2021 AAHA Nutrition and Weight Management Guidelines and Merck use the same two steps:

1. Resting energy requirement (RER) — the calories burned at rest: 70 × body weight in kg^0.75.
2. A growth factor: 3.0 × RER before 4 months of age, 2.0 × RER from 4 months until adult size.

The result is the maintenance energy requirement (MER) for a growing puppy, in kilocalories (kcal) a day — the same unit as the “Calorie” on a human food label.

“4 months” needs a definition, because a week can change the answer. With an age in weeks, our calculators treat anything under 17.4 weeks as under 4 months, so a puppy is on 3.0 at 17 weeks and 2.0 at 18 weeks. With a birth date, the switch happens on the calendar date 4 months after birth: a puppy born June 7, 2026, moves to 2.0 on October 7, 2026.

The numbers explain why puppies seem to eat so much. An 8-kg (17.6-lb) puppy at 13 weeks comes out at 999 kcal a day, about twice the 499 kcal of a neutered adult dog of the same weight — in line with the National Research Council’s owner guide, which says a growing puppy starts out needing about twice the calories per pound of an adult of the same breed.

Four puppies, worked through

The table runs four example puppies through the rule. The cups and grams assume a dry food whose label says 380 kcal per cup and 3,600 kcal per kg, with 10% of the day’s calories set aside for treats — the upper limit, since Merck keeps treats under 10% of the total.

Take the first row, a 12-week-old toy puppy. Its RER is 52 kcal; three times that is 157 kcal a day. After 16 kcal for treats, 142 kcal of food is 0.37 cups — or 39 g, which is easier to measure exactly. Split over three meals, that is about 13 g a meal.

The range column is not decoration. Merck notes that any animal may need as much as 30% more or less than the calculated amount, and WSAVA’s owner FAQ says adult dogs and cats can vary by up to 50%. The calculated number is where you start; the scale tells you where to go next.

The NRC growth equation: an upper reference

You will also meet a second formula, the National Research Council’s 2006 growth equation, as quoted in peer-reviewed papers: 130 × kg^0.75 × 3.2 × (e^(−0.87 × p) − 0.1), where p is today’s weight divided by the expected adult weight. It needs an adult-weight estimate, and it gives higher numbers than the AAHA rule for these four puppies:

Two studies measured what small-breed puppies actually needed. In Yorkshire terriers, the NRC equation overestimated energy needs from 10 to 20 weeks of age; in Norfolk terriers, it overestimated them throughout the first year. That is why our puppy feeding calculator gives the AAHA rule as the answer and shows the NRC equation only as an upper reference line.

From calories to cups and grams

Calories become food through the label. Under AAFCO’s model rule, U.S. pet-food labels carry a “Calorie Content” statement in kcal per kg and kcal per cup or can. Divide the daily food calories by the kcal per cup for cups, or by the kcal per kg and multiply by 1,000 for grams. Puppy foods vary a lot in energy density, so never borrow the cup count from a different food. More on reading the statement in dog food labels and kcal per cup.

Weighing is more precise than scooping, especially for toy puppies whose whole day’s food fits in a few tablespoons.

How many meals a day

Merck’s general recommendation is three meals a day from weaning to 6 months of age and two meals a day from 6 to 12 months; small-breed puppies may need more than three. Your vet can suggest a schedule that suits your puppy and your day. The number of meals changes how you split the food, not how much the puppy eats in a day.

Puppies younger than 8 weeks are usually still nursing or weaning, and our calculator doesn’t estimate them; ask your vet or the breeder. Merck notes that growth may be complete by 8–12 months in small and medium breeds but may run to 10–16 months in large and giant breeds; our calculator suggests adult factors from 12 months. Large-breed puppies also need a slow, lean growth plan, covered in feeding a large-breed puppy.

Weigh, look, adjust

1. Weigh your puppy weekly if you can — Merck advises watching weight gains closely, week by week, and adjusting the food so the puppy keeps gaining a small amount each week.
2. Check body condition at the same time: you should be able to feel the ribs under a thin layer of fat and see a waist from above.
3. Recalculate with the new weight. The calories go up as the puppy grows, then drop at the 4-month step.
4. Adjust at least every 2 weeks at first. WSAVA’s nutrition FAQ advises adjusting the starting amount every 2 weeks until your pet holds an ideal weight and body condition.
5. Tell your vet if your puppy stops gaining, loses weight, or looks heavier than the descriptions above.

Next step

Put your puppy’s age, weight and food label into the puppy feeding calculator. It applies the 3.0 or 2.0 factor, shows the ±30% range and the NRC reference line, and turns the answer into cups and grams per meal for your food.