Dog Food Calculator | Daily Calories & Portions

The formula is 70 × kg^0.75 — the veterinary standard for Resting Energy Requirement. The 0.75 exponent means calorie needs don't scale linearly with body weight. A 40kg dog needs less than twice what a 20kg dog needs. Larger animals are thermally more efficient.

After the RER, a life stage multiplier is applied. A puppy under 4 months needs 3.0× its RER. A neutered adult needs 1.6×. Enter your dog's weight, life stage, body condition score, and the calorie density from your food label.

The RER Formula: Why 70 × kg^0.75

The 0.75 exponent comes from research by Max Kleiber in 1932, confirmed across hundreds of mammal species. Larger animals are more thermally efficient — proportionally less surface area to lose heat through. A 2kg Chihuahua needs about 95 kcal per kilogram per day; a 60kg Great Dane needs roughly 35.

A flat per-kilogram rate would dramatically overfeed large breeds and underfeed small ones. The RER × life stage multiplier approach is the standard used by AAFCO and the National Research Council.

Life Stage Multipliers: Where Most of the Variation Lives

Puppies under 4 months use 3.0× — bones are mineralising, organs growing, immune system developing. From 4 to 12 months, the multiplier drops to 2.0× as rapid growth slows. The difference between intact adult (1.8×) and neutered adult (1.6×) surprises many owners.

Spaying or neutering reduces resting metabolic rate by 20–25%. Senior dogs at 1.4× are typically less active. Working dogs on active days can hit 2.8×.

Body Condition Score: The Feedback Loop

Weight alone doesn't capture body composition. A 30kg dog at BCS 8 has much more body fat than a 30kg dog at BCS 5. Since fat is metabolically less active than muscle, the obese dog needs fewer calories per kilogram.

To assess BCS at home: press gently on your dog's ribcage. At BCS 5, you feel individual ribs easily without pressing hard. The waist is visible from above. There's a slight abdominal tuck from the side. Scores 7–9 mean ribs need firm pressure. Target no more than 1–2% body weight loss per week.

Dry vs Wet Food: The Calorie Density Gap

Dry kibble is typically 300–420 kcal per cup. Wet canned food is 150–200 kcal per 400g can — less calorie-dense because it's 70–80% water. The same daily calorie target produces much larger physical portions with wet food.

Always use the calorie values from your specific food label. Calorie density varies meaningfully between brands, formulations, and flavours within the same product line.

Treats and the 10% Rule

Commercial treats are often more calorie-dense than they look. A single medium dog biscuit is 40–80 kcal. A small piece of cheese is about 60 kcal. The 10% guideline exists because above that threshold, treats displace significant amounts of nutritionally complete main food.

The treat slider adjusts the kibble portion automatically — adding 100 kcal of treats removes 100 kcal from the main food portion.