Feeding your dog the right amount every day is one of the most important things you can do for their long-term health. Too little food leads to nutritional deficiencies and low energy, while overfeeding is a leading cause of canine obesity, joint problems, and metabolic diseases. Knowing the correct daily portion takes the guesswork out of mealtime. This dog food calculator uses the standard veterinary energy model to estimate your dog's daily caloric needs and converts them into practical gram measurements for both dry and wet food. The calculation starts with RER (Resting Energy Requirement) — the calories needed to sustain basic body functions at rest: RER = 70 × bodyweight^0.75 kcal/day. This is then multiplied by a life-stage factor to produce the MER (Maintenance Energy Requirement): puppy 2.8, adult 1.4, senior 1.2, active/working 1.8, neutered/spayed 1.2. The MER is then divided by the calorie density of your chosen food (kcal/kg) to give daily grams of dry food. For wet food, a standard density of 800 kcal/kg is assumed. These results are a starting point — always cross-check with the feeding guide on your food's packaging and consult your vet for dogs with health conditions or special dietary needs.
The calculator uses the standard energy model employed by veterinary nutritionists worldwide. **Step 1 — RER (Resting Energy Requirement):** The baseline energy need is calculated as RER = 70 × bodyweight^0.75 kcal/day. This formula accounts for the non-linear relationship between metabolism and body mass — larger dogs require proportionally fewer calories per kilogram than smaller breeds. **Step 2 — MER (Maintenance Energy Requirement):** Actual daily needs depend on life stage and activity. We multiply RER by the appropriate factor: puppy 2.8 (rapid growth), adult 1.4 (normal activity), senior 1.2 (slower metabolism), active/working 1.8 (sport, herding, intensive exercise), neutered/spayed 1.2 (reduced metabolic rate post-surgery). **Step 3 — converting to grams:** MER is divided by the food's caloric density (kcal/kg) and multiplied by 1000 to get grams. For wet food, a default of 800 kcal/kg is used. Note that these are population-average formulas. An individual dog may need ±20% relative to the calculated value depending on breed, individual metabolism, and health status. Regular body condition scoring is the best way to fine-tune portions.
Let's calculate the daily food portion for a 30 kg adult Labrador eating dry food rated at 3600 kcal/kg. Step 1 — RER: 70 × 30^0.75 = 70 × 12.83 ≈ 898 kcal/day. Step 2 — MER: 898 × 1.4 (adult factor) ≈ 1257 kcal/day. Step 3 — dry food: (1257 / 3600) × 1000 ≈ 349 g/day. Step 4 — wet food alternative: (1257 / 800) × 1000 ≈ 1571 g/day. In practice, this Labrador should receive about 350 g of dry food per day, split into two meals — morning and evening. If feeding wet food exclusively, approximately 1.6 kg per day is needed. For mixed feeding, reduce both portions proportionally according to the calorie split.
A 15 kg adult dog has an MER of approximately 652 kcal/day. For dry food rated at 3500 kcal/kg, that works out to about 186 g per day. For wet food (800 kcal/kg), you would need around 815 g. Always verify with the feeding guide on your specific food packaging.
RER (Resting Energy Requirement) is the energy a dog needs just to stay alive at rest — calculated as 70 × weight^0.75. MER (Maintenance Energy Requirement) adds the real-world activity and life-stage multiplier: 1.4 for a normal adult, 2.8 for a puppy, 1.8 for a highly active dog. MER is what you actually feed.
Puppies have a much higher energy demand due to rapid growth — the MER multiplier is 2.8, meaning they need twice as many calories as an adult dog of the same weight. Divide the daily amount into 3–4 small meals until 6 months old, then move to 2–3 meals. Always use a puppy-specific formula food.
Senior dogs (typically 7+ years for medium breeds, 5+ for large breeds) have a slower metabolism. Their MER factor is 1.2, meaning about 14% fewer calories than a standard adult. Choose a senior-formula food with adjusted protein and joint-supporting nutrients like glucosamine.
Both have advantages. Dry kibble is calorie-dense, easy to store, helps dental hygiene, and is cost-effective. Wet food has higher moisture content (good for hydration), is more palatable for picky eaters, and easier to chew for seniors. Many owners successfully combine both. If mixing, calculate portions based on each food's calorie contribution.
Wet food is much less calorie-dense than dry food — typically around 800 kcal/kg (vs 3000–4000 kcal/kg for dry). The calculator uses this standard value for wet food grams. For your specific product, divide your dog's MER (kcal/day) by the food's listed kcal/kg and multiply by 1000.
Adult dogs are typically fed twice a day (morning and evening). Puppies under 3 months need 4 meals, up to 6 months need 3 meals. Senior dogs may benefit from 2–3 smaller meals to ease digestion. The total daily amount stays the same regardless of how many meals you split it into.
Yes. Highly active dogs — working breeds, sport dogs, or those doing 2+ hours of vigorous exercise daily — have an MER factor of 1.8, approximately 29% more than a standard adult. Adjust portions upward during high-activity periods and reduce during rest or recovery periods.
Neutering reduces a dog's metabolic rate, and the risk of weight gain increases significantly post-surgery. The MER factor drops to 1.2 — the same as a senior dog. It is important to reduce food portions after neutering (or switch to a neutered/light formula) and monitor body weight closely.
No. The calculator provides a scientifically-grounded estimate using standard veterinary energy formulas. However, individual dogs vary — breed, body condition score, health status, and specific food composition all affect real needs. Always consult a vet or certified veterinary nutritionist for dogs with chronic illness or unusual dietary requirements.
Indicative portion only — consult your veterinarian. Calculator results are based on standard energy formulas and do not replace individual dietary or veterinary advice.
Calculate how many calories your dog needs per day. The RER and MER calculator accounts for weight, age, activity level and physiological status (pregnancy, nursing, obesity). Also shows dry and wet food amounts.