Pet Food Calculator
Calculate daily pet food portions from weight, activity level, and calorie density per cup.
Covers dogs, cats, and small animals with age adjustment factors.
Pet daily food portion calculation determines the correct amount of food to feed your dog or cat each day based on weight, life stage, and the caloric density of the specific food you’re using.
Core formula: Daily Food Amount = Daily Calorie Need ÷ Food Calories per Cup (or per kg)
Step 1 — Calculate Resting Energy Requirement (RER): RER (kcal/day) = 70 × Body Weight (kg)^0.75
Simplified linear approximation for most pets: RER ≈ 30 × Weight (kg) + 70
Step 2 — Apply life stage multiplier: Daily Energy Requirement (DER) = RER × Life Stage Factor
| Life Stage | Multiplier |
|---|---|
| Neutered adult | 1.6 |
| Intact adult | 1.8 |
| Puppy (< 4 months) | 3.0 |
| Puppy (4 months to adult) | 2.0 |
| Senior dog (7+) | 1.4 |
| Pregnant dog (last 3 weeks) | 3.0 |
| Nursing dog | 4.0–8.0 |
| Weight loss (dog) | 1.0 |
| Adult neutered cat | 1.2 |
| Active adult cat | 1.4 |
Step 3 — Divide by food caloric density: Most dry kibble: 300–400 kcal/cup (check the label — it must be listed by AAFCO) Most wet food: 100–200 kcal/can
Worked example: A 10 kg (22 lb) neutered adult Labrador: RER = 70 × (10)^0.75 = 70 × 5.62 = 393 kcal/day DER = 393 × 1.6 = 629 kcal/day Kibble density: 350 kcal/cup Daily portion = 629 ÷ 350 = 1.8 cups per day (split into 2 meals)
Important: These are starting points. Adjust based on body condition score (BCS). A BCS of 5/9 is ideal — you should feel (but not see) the ribs. Reduce by 10–20% if your pet is gaining weight; increase if losing. Always have fresh water available.