Why does kcal-per-cup matter so much?

Food energy density varies wildly across brands and formulations. The same cup of one food might be 320 kcal and another 450 kcal. A calculator that doesn't take kcal-per-cup as an input will always be wrong by a meaningful margin.

How often should I adjust the portion?

Every two to four weeks, with a body-condition check. If your dog is drifting heavier, reduce by 10%; if drifting lighter, increase by 10%. Keep treats under 10% of daily calories.

What about wet / fresh / raw food?

The calculator works for any food type as long as you know the kcal density. Fresh and raw foods often have lower kcal/cup than kibble, so the cup count goes up — the calorie target is the same.

CalculatorFood

Dog Food Calculator

Daily cups, grams, and calories for your dog — based on NRC 2006 energy requirements. Adjusts for activity, life stage, and food density.

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Formula

How this calculator works

NRC 2006 Maintenance Energy Requirement (MER) with AAFCO life-stage multipliers.

How this calculator works

Four components: RER from body weight, MER from RER + activity + stage, conversion to cups via food density, and a sanity-check split across meals.

1
rer = 70 × (kg)^0.75
Resting Energy Requirement. A 20-kg dog's RER is roughly 665 kcal/day before any activity or life-stage factor.
NRC 2006 Nutrient Requirements of Dogs and Cats.
2
mer = rer × activityFactor × stageFactor
Maintenance Energy Requirement multiplies RER by an activity factor (1.2 sedentary → 3.0 working) and a life-stage factor (puppies and working adults need more than couch-adult dogs).
NRC 2006; AAFCO life-stage multipliers.
3
dailyCups = mer / kcalPerCup
Divide by the kcal-per-cup density printed on the back of the food bag. Typical adult-maintenance dry food is 350–430 kcal/cup.
AAFCO food-label reference.
4
split across meals
For adult dogs, two meals per day is standard. Puppies often benefit from three or four smaller meals until around six months.
AAHA Nutrition Guidelines.

Context

When to use this calculator

Use this any time you switch foods (different kcal/cup), adjust activity (new exercise pattern or season), or when your dog's body condition drifts from ideal. The calculator gives you a defensible starting portion; a two-week body-condition check calibrates it.

For prescription diets or medical-weight-management scenarios, the veterinarian-prescribed portion always wins over this calculator.

FAQ

Frequently asked

Why does kcal-per-cup matter so much?
Food energy density varies wildly across brands and formulations. The same cup of one food might be 320 kcal and another 450 kcal. A calculator that doesn't take kcal-per-cup as an input will always be wrong by a meaningful margin.
How often should I adjust the portion?
Every two to four weeks, with a body-condition check. If your dog is drifting heavier, reduce by 10%; if drifting lighter, increase by 10%. Keep treats under 10% of daily calories.
What about wet / fresh / raw food?
The calculator works for any food type as long as you know the kcal density. Fresh and raw foods often have lower kcal/cup than kibble, so the cup count goes up — the calorie target is the same.