How much to feed a dog by weight (kg)?

Feeding a dog by weight is one of the most practical steps an owner can take to keep their pet healthy. Rather than guessing with “cups,” working from body weight and the energy density of the food lets you match intake to a dog’s real needs — whether the goal is steady growth, everyday maintenance, losing excess weight, or supporting a sporting schedule.

Weight: the most important factor in portioning your dog’s meals

Owners often rely on package cups or rules of thumb, which may be fine for a rough start but can leave a dog under- or over-fed for months. A dog’s ideal food amount depends on its size, body composition, activity, life stage and health — details that a single cup recommendation can’t capture. Weight-based feeding helps with predictable outcomes: controlled growth in puppies, precise calorie restriction for weight loss, and correct refueling for working or sporting dogs.

Typical situations where weight-based feeding matters include mixed-household homes with dogs of very different sizes, dogs recovering from illness, pets needing slow, steady weight loss, and growing puppies whose calorie needs change rapidly. I typically see owners underestimate how many calories a medium dog needs during athletic work, and overestimate calories when a dog is largely sedentary after neutering. In those cases, weight-based calculations tend to be more useful than visual estimates.

Feeding by weight is not a replacement for professional advice. If your dog has a chronic disease, is pregnant, lactating, or you suspect a metabolic disorder, involving your veterinarian or a veterinary nutritionist is the safest approach.

A quick, at-a-glance guideline for daily food per kg

For a fast, actionable starting point, use these steps: (1) calculate the dog’s resting energy requirement (RER), (2) multiply by a factor that fits the life stage/activity, and (3) convert kcal into grams using the food’s energy density. A standard RER formula many clinicians use is RER = 70 × (body weight in kg)^0.75. Typical multipliers to estimate maintenance energy (MER) are roughly 1.2–1.6 × RER for neutered or low-activity adult dogs, 1.6–2.0 × RER for intact/active adults, and higher for growth or lactation.

As broad kcal/kg guides, smaller dogs often end up needing about 55–75 kcal/kg/day, medium dogs about 45–60 kcal/kg/day, and large dogs about 40–50 kcal/kg/day — but these are averages that may not fit every individual because kcal/kg tends to fall with increasing body size.

1. Example: a 10 kg neutered adult. RER ≈ 70 × 10^0.75 ≈ 393 kcal. MER (1.4×RER) ≈ 550 kcal/day. If the food is 350 kcal per 100 g (3.5 kcal/g), feed ≈ 550 ÷ 3.5 ≈ 157 g/day.

2. Example: a 20 kg moderately active adult. RER ≈ 70 × 20^0.75 ≈ 662 kcal. MER (1.4×RER) ≈ 927 kcal/day. At 350 kcal/100 g, feed ≈ 927 ÷ 3.5 ≈ 265 g/day.

3. Example: a 5 kg toy dog. RER ≈ 70 × 5^0.75 ≈ 234 kcal. MER (1.4×RER) ≈ 328 kcal/day. At 350 kcal/100 g, feed ≈ 328 ÷ 3.5 ≈ 94 g/day.

Adjust immediately if your dog is very active (increase by about 10–30% depending on intensity) or very sedentary/older (decrease by about 10–20%), then recheck weight and body condition in a few weeks.

Why two dogs the same weight can need different portion sizes

A dog’s energy needs are the sum of several biological demands. Basal metabolic rate (the energy to support basic life processes) forms the baseline; maintenance energy includes routine activity and digestion. Growth, pregnancy and lactation add substantial extra needs: a lactating dam may require double or more her maintenance energy because of milk production.

Body composition matters: two dogs of the same weight with different muscle mass may have different caloric requirements since muscle is more metabolically active than fat. Hormonal status also likely affects appetite and energy use — for example, neutering often lowers typical energy needs, while thyroid disease or steroid medications can change appetite and body condition.

Because metabolism is individual, breed, age and previous nutrition history can influence how many calories a given dog should receive. Regular monitoring of weight and body condition is the practical way to see whether the metabolic estimate matches reality.

Recognizing life events that change a dog’s calorie needs

Life stage transitions are frequent triggers to rework feeding plans. Puppies need steadily increasing calories per kg as they grow, typically peaking in kcal/kg and tapering as they approach adult size. Seniors may slow down and need fewer calories, or, conversely, they may lose weight and need more concentrated nutrition if muscle wasting occurs.

Activity shifts — new training, beginning agility or hunting, or a sudden period of rest after an injury — change calorie needs quickly. Environmental temperature also plays a role: dogs exposed to cold for long periods may need extra calories, while heat stress can suppress appetite. Illnesses and many medications influence appetite and nutrient use; chemotherapy, steroids, anticonvulsants and thyroid treatments are examples that may alter feeding requirements or body weight trajectory.

Warning signs your dog’s portions need revising

Gradual, unexplained weight gain or loss should prompt recalculation and possibly veterinary assessment. Aim to notice a change of 5–10% of body weight; it can signal that intake and energy needs are mismatched or that an underlying problem exists. Body condition score (BCS) is a complementary tool — two dogs can weigh the same but have different proportions of muscle and fat.

Coat quality and energy levels often change with poor nutrition: a dull coat, excessive shedding, or persistent fatigue may suggest the feeding plan is not meeting needs. Gastrointestinal signs like repeated vomiting, diarrhea, or very loose stools may indicate intolerance to the food, overfeeding, or a medical issue and should be addressed sooner rather than later.

Recognize acute emergencies: collapse, extremely labored breathing, sudden severe vomiting or diarrhea, or signs of an allergic reaction (hives, facial swelling, difficulty breathing) require immediate veterinary attention. These are not problems to manage with portion resizing at home.

From kilograms to grams: calculate daily portions and adjust safely

Step 1 — Decide the target weight and realistic body-condition goal. If your dog is overweight, aim for a healthy target weight rather than an idealized trimness. Step 2 — Calculate RER with 70 × (kg)^0.75 and choose an appropriate multiplier for the life stage or activity. Step 3 — Find the food’s calorie density (kcal per 100 g or kcal per cup) from the packaging or manufacturer and convert to kcal per gram.

Step 4 — Divide the daily kcal target by kcal per gram to get grams per day, and split that total across feeding sessions. If you must use cups, weigh a single cup on a kitchen scale to determine grams per cup because cup volumes vary between foods. Step 5 — Implement changes gradually; a 10–20% daily calorie adjustment spread over 7–14 days usually helps digestion and appetite adapt. I usually advise owners to avoid abrupt large cuts unless directed by a veterinarian for specific medical reasons.

Step 6 — Recheck weight and body condition at 2–4 weeks and adjust further if necessary. If weight fails to change toward the goal after a reasonable period, or if there are signs of illness, escalate to your veterinarian or a board-certified veterinary nutritionist for tailored assessment and a plan.

Make mealtimes work: routine, timing and training tips

Scheduled meals give control over total daily calories and are helpful for weight management; free-feeding often leads to excess intake in dogs that will graze. For puppies and dogs with high energy needs, multiple small meals may stabilize energy and reduce begging.

Slow feeders and puzzle feeders reduce gulping and extend the time dogs spend eating, which may slow consumption and increase mental stimulation. When training, budget treats into the daily calorie total: treats should generally be less than about 10% of daily calories for most goals, and low-calorie options (small pieces of cooked lean meat, baby carrots, or commercial low-cal treats) work well during high-frequency training sessions.

In multi-dog households, separate feeding stations prevent guarding and ensure each dog gets its allotted portion. A simple routine — consistent timing and designated bowls — helps reduce anxiety around food and makes portion control easier for everyone in the house.

Practical tools for accurate feeding — scales, cups and apps

A digital kitchen scale is the single most useful tool for weight-based feeding; weighing grams is far more accurate than relying on cups. Calibrated measuring cups and clearly labeled storage containers speed repeatable portioning. Slow-feed bowls and food-dispensing puzzles are practical for pacing meals and providing enrichment. For treats, keep a small container with pre-portioned pieces so you can count treats without guessing calories. Automatic feeders can help with consistent meal timing in households with variable schedules, but they still require careful portion programming and monitoring.

References: studies, veterinary guidance and feeding charts

• NRC: Nutrient Requirements of Dogs and Cats (National Research Council, 2006) — tables and guidance on energy and nutrient needs.
• AAFCO Official Publication: Dog Food Nutrient Profiles and Feeding Statement Guidance — standards used for commercial pet food labeling.
• WSAVA Global Nutrition Toolkit (World Small Animal Veterinary Association, 2017) — practical nutrition recommendations for clinicians and owners.
• Merck Veterinary Manual: Canine Nutrition and Feeding — clinical overview of nutritional needs and feeding practices.
• American College of Veterinary Nutrition (ACVN) — resources for finding a board-certified veterinary nutritionist and position statements on clinical feeding.