How much dry food should you feed your dog or cat?
Enter your pet's weight, life stage and activity level. You'll get a daily portion in cups, grams and pounds — plus the full calculation behind it, so you can check the math yourself.
Feeding calculator
How this calculator works
Every credible pet feeding calculator runs the same two-stage sequence. The numbers come from the National Research Council's Nutrient Requirements of Dogs and Cats (2006), the reference document behind the WSAVA Global Nutrition Guidelines. Factor values are cross-checked against Hand, Thatcher, Remillard, Roudebush & Novotny (eds.), Small Animal Clinical Nutrition, 5th ed. (Mark Morris Institute, 2010) — the textbook on the American College of Veterinary Nutrition board reading list.
Step 1 — Resting Energy Requirement (RER). The energy your pet burns at complete rest:
The 0.75 exponent is Kleiber's Law. Metabolic rate scales to roughly the three-quarter power of body mass, not to mass itself — which is why a 40 kg dog does not need four times the calories of a 10 kg dog. We deliberately avoid the linear shortcut (30 × kg + 70): it only holds between about 2 kg and 45 kg and drifts badly outside that band.
Step 2 — Maintenance Energy Requirement (MER). RER multiplied by a life-stage and activity factor, matched top-down from the tables below (life stage takes precedence over activity).
Step 3 — Convert calories into food. Divide MER by the calorie density printed on your bag.
If your bag lists kcal/kg instead, we convert to grams by dividing MER by the kcal/kg figure and multiplying by 1,000.
Factor tables used
These are the standard NRC / WSAVA maintenance factors. Life stage takes precedence: a puppy's row overrides the adult rows.
Dogs
| Condition | Factor |
|---|---|
| Puppy, under 4 months | 3.0 |
| Puppy, 4–12 months | 2.0 |
| Senior, 7 years and over · active or working | 1.5 |
| Senior, 7 years and over · typical or low activity | 1.35 |
| Adult, neutered, working | 2.5 |
| Adult, neutered, active | 2.0 |
| Adult, neutered, typical | 1.6 |
| Adult, neutered, low activity | 1.4 |
| Adult, intact, working | 2.5 |
| Adult, intact, active | 2.0 |
| Adult, intact, typical | 1.8 |
| Adult, intact, low activity | 1.6 |
| Weight-loss plan (uses target weight) | 1.0 |
Cats
Cats are not small dogs. Their maintenance factors are markedly lower, and the weight-loss factor is different for a specific physiological reason (see the safety note below).
| Condition | Factor |
|---|---|
| Kitten, under 4 months | 2.5 |
| Kitten, 4–12 months | 2.0 |
| Senior, 11 years and over | 1.1 |
| Adult, neutered, active or outdoor | 1.4 |
| Adult, neutered, typical indoor | 1.2 |
| Adult, neutered, sedentary | 1.0 |
| Adult, intact, active | 1.6 |
| Adult, intact, typical | 1.4 |
| Adult, intact, sedentary | 1.2 |
| Weight-loss plan (uses target weight) | 0.8 |
Two notes on reading these tables. Senior dogs are split by activity because the NRC lists separate multipliers for them — in its words, “older active dogs = 105, inactive dogs = 95” kcal per kg0.75, which on this scale is 1.5 against 1.35. Collapsing the two into one figure would underfeed an active older dog. And the weight-loss row does not distinguish neutered from intact animals: during weight loss the controlling variables are the target weight and the weekly rate of loss, not neuter status.
Why the cat senior age is 11 and the dog senior age is 7: they are different species with different lifespans, so a single threshold would be wrong for one of them. Eleven comes from the AAFP–AAHA Feline Life Stage Guidelines, which divide older cats into mature (7–10 years), senior (11–14) and geriatric (15 and over) — eleven is the start of the senior band, not a round number. Seven for dogs is the conventional simplification, and it is worth knowing what it hides: AAHA defines canine senior status as roughly the final quarter of expected lifespan rather than a fixed age, which for very small breeds can mean nine or ten and for giant breeds as early as five or six. Treat the seven-year line as a prompt to start checking rather than a biological switch.
A note on accuracy. A 2014 meta-analysis by Bermingham and colleagues pooled 70 treatment groups from 29 published studies and found mean maintenance energy requirements of 142.8 ± 55.3 kcal per kg0.75 per day. That mean sits above the figure a typical neutered pet dog gets here (about 112 kcal per kg0.75), and the same paper explains why: requirements were highest in racing and working dogs and lowest in pet and kennel dogs, so a mean taken across all of them is not the right number for a dog on the sofa. The standard deviation is the more useful finding. Two pets that look identical on paper can differ by hundreds of calories a day, which is why this calculator gives you a number to test rather than a number to trust.
Frequently asked questions
How many cups of dry food should I feed my dog per day?
It depends on your dog's weight, life stage, activity level, and the calorie density of the specific food. A worked reference: a 30 lb (13.6 kg) neutered adult dog of typical activity has a resting energy requirement of 496 kcal/day, which becomes 794 kcal/day once the 1.6 life-stage factor is applied — about 2.14 cups of a 370 kcal/cup kibble, or 2.27 cups of a 350 kcal/cup kibble. Enter your own numbers above for an exact figure, or see the full weight chart by size.
Why doesn't this match the feeding chart on my bag?
Bag charts are broad starting points written for large groups of pets at once. They are built from the same RER × MER math, but many manufacturers tend to round upward and assume generous activity levels, and some label specifically for neutered indoor pets instead. A calorie calculator works from your pet's metabolic body weight and your food's actual energy density, so the two frequently disagree. Use body condition and weight trend over the next few weeks to judge which starting point is right for your pet.
Which number on the bag do I use, kcal/cup or kcal/kg?
Either — the calculator handles both. US bags print both figures, for example 3,700 kcal/kg, 370 kcal/cup. Cups are the more convenient unit for dry food because you can scoop them. If your bag only lists kcal/kg and grams per cup, enter kcal/kg and our default 110 g per cup, or enter your bag's stated grams-per-cup value for a more precise gram figure.
Do treats and table scraps count?
Yes. Treats, dental chews, training rewards and table scraps all come out of the same daily calorie budget. A common starting point is treats at 10% or less of daily calories. On a weight-loss plan, uncounted extras are one of the most common reasons progress stalls.
How often should I change the amount I feed?
Treat the result as a starting estimate and reassess after about 2 to 4 weeks. If body weight is drifting, the waist is disappearing, the ribs are becoming too hard or too easy to feel, or stool quality worsens, adjust gradually. Small corrections backed by repeated observations work better than large jumps.
Is this calculator suitable for puppies, kittens, or pets with medical conditions?
It gives a useful starting estimate for healthy growing pets, but puppies, pregnant or nursing animals, very large breeds, working dogs, and pets with conditions such as pancreatitis, kidney disease or recovery from illness need a more individualised plan. In those cases confirm the result with your veterinarian rather than relying on the calculator alone.
Is this veterinary advice?
No. This is an estimation tool. It is not veterinary medical advice, and it does not diagnose or treat anything. Always consult your local veterinarian for your pet's specific dietary needs.
Feeding guides
Longer explanations of the numbers behind the calculator.
- Dog treat calculator: how many treats can my dog have? — the 10% rule worked out for your dog, the treats owners forget to count, and what to do when you are over the limit.
- How much should I feed my dog? A weight chart by size — adult dog chart from 5 lb to 120 lb, and how to adjust it for your food's calorie density.
- How to read the calorie information on your pet food bag — where the number is printed, kcal/kg versus kcal/cup, and the unit mistake that throws portions off tenfold.
- Body condition score: is your pet the right weight? — the three hands-on checks, what each of the nine score bands means, and how to change the amount safely.
- How long does a bag of dog food last? — days per bag by bag size and body weight, and whether the bag is larger than your pet can eat while it is still fresh.
- What does it cost to feed a dog? — cost per day, month and year, and why a food that is cheaper per kilogram can be more expensive to actually feed.
- How many cups are in a pound of dog food? — the reference tables, a converter for your own kibble, and why the answer is a range rather than a number.
- How to measure dog food without a scale — five methods ranked by accuracy, how to calibrate a scoop with water, and what a 10% scooping error costs over a year.
- My dog is overweight: a safe, gradual feeding plan — six steps from confirming the problem to reaching the target, and how fast is safe.