How Much Should I Feed My Dog Per Day? (Vet Formula)

Updated May 20, 2026

Most adult dogs need about 25 to 30 calories per pound of body weight per day, but the vet formula is more accurate because it scales with metabolism, not just weight. A 30-pound neutered adult typically needs around 750 to 800 kcal/day, which usually works out to 2 to 2.5 cups of dry food depending on the brand.

The NRC Vet Formula (and Why It Beats the Bag)

Veterinary nutritionists use a two-step calculation from the National Research Council:

Resting Energy Requirement (RER): 70 × (body weight in kg)^0.75
Maintenance Energy Requirement (MER): RER × an activity factor

The activity factor depends on your dog's life stage and lifestyle:

Neutered adult: 1.6 × RER
Intact adult: 1.8 × RER
Weight loss: 1.0 × RER
Weight gain: 1.7 × RER
Light work / active: 2.0 × RER
Puppy under 4 months: 3.0 × RER
Puppy 4 months to adult size: 2.0 × RER

Bag labels overshoot for one reason: they're written for the most active dog of that weight, plus a safety margin so you don't run out and switch brands. Most companion dogs are couch dogs with a 20-minute walk. Following the bag will add weight on roughly half the dogs that eat it.

Worked Example: 30-lb Beagle, Neutered, Moderate Couch Life

Convert weight: 30 lb ÷ 2.2 = 13.6 kg.

RER = 70 × (13.6)^0.75 = 70 × 7.07 = 495 kcal/day

MER for a neutered adult = 495 × 1.6 = ~792 kcal/day

Now convert calories to cups. Find the "metabolizable energy" or "kcal/cup" on your bag (often in small print on the back, sometimes only on the manufacturer's website). A typical adult kibble runs 330 to 420 kcal/cup.

Kibble at 350 kcal/cup: 792 ÷ 350 = ~2.3 cups/day
Kibble at 400 kcal/cup: 792 ÷ 400 = ~2.0 cups/day

Same dog, same hunger, different cup count. That's why "the bag says 2.5 cups" can be wildly wrong if you switched brands recently.

You can run your dog's numbers in the PawMath food portion calculator so you don't have to do the exponent by hand.

Adjust for Age and Body Condition

Senior dogs (roughly 7+ for large breeds, 10+ for small breeds) often need 10 to 20% fewer calories than the MER suggests. Their resting metabolism drops and most are less active. If you're not sure where your dog falls age-wise, the dog age calculator gives a breed-size-adjusted human equivalent.

Puppies are the opposite. A 4-month-old Lab puppy projected to weigh 70 lb as an adult can burn through 1,400 to 1,600 kcal/day during peak growth. Underfeeding puppies risks growth plate issues. Overfeeding large-breed puppies risks orthopedic problems. Stick to a puppy-formulated food and weigh weekly.

The honest gut-check is body condition score (BCS), a 1 to 9 scale your vet uses:

You should feel ribs easily under a light fat cover (not see them, not hunt for them)
There should be a visible waist behind the ribcage when viewed from above
A tucked abdomen when viewed from the side

If your dog's BCS is 6 or 7, cut intake 10 to 20% and recheck in three to four weeks. Don't crash-diet a dog. Aim for 1 to 2% body weight loss per week.

Treats Are Calories Too

The 10% rule: treats and chews shouldn't push past 10% of daily calories. For our 30-lb Beagle, that's about 80 kcal of treats. One standard dental chew can be 80 to 120 kcal. One piece of cheese cube? About 70. People feed way more treats than they think.

Subtract treat calories from the food portion, not in addition to it.

Wet Food, Toppers, and Fresh

If you're mixing wet food, fresh food, or a topper like Raw Wild into kibble, do the math on calories, not volume. A 13-oz can of wet typically runs 350 to 475 kcal. One scoop of a freeze-dried topper might add 60 to 90 kcal. Cut the kibble by whatever you add elsewhere.

For owners cooking at home, a batch-cook appliance like ChefPaw gives you a per-batch kcal estimate, which makes portioning easier than freestyling chicken and rice on the stove.

When to Recheck Portions

Reweigh your dog and recalculate every:

4 weeks for puppies (they grow fast)
6 months for adults
3 months for seniors or any dog on a weight plan
Anytime you change food brands or formulas

Five extra pounds on a 30-lb dog is the human equivalent of 25 to 30 extra pounds. It shortens lifespan, hammers joints, and roughly doubles the risk of diabetes and certain cancers. A 2019 lifetime study of Labradors (Salt et al., Journal of Veterinary Internal Medicine) found lean-fed dogs lived a median 1.8 years longer than overfed littermates. That's the entire ROI of getting the cup count right.

Run your dog's exact numbers here: PawMath food portion calculator.

Tools mentioned in this guide

Food Portion Calculator

Daily kibble cups from the NRC RER veterinary formula, scaled to your bag's kcal-per-cup.