There is a formula. The honest headline is how wide it is.
FEDIAF’s Nutritional Guidelines reviewed the published research and found allowances for adult dogs running “from less than 90 kcal ME/kg^0.75 (377 kJ) to approximately 200 kcal ME/kg^0.75 (810 kJ).”
Strip the notation and that means this. For a 20 kg dog, somewhere between 850 and 1,890 calories a day. Same dog, same research, a 2.2-fold span.
That is not a reason to ignore the formulas. It is a reason to treat the answer as a starting point, and the dog as the real measuring device.
The base number
Every method starts from the same idea. You cannot scale calories straight off bodyweight, because a big dog burns less per kilo than a small one. So the tables use metabolic bodyweight: bodyweight raised to the power 0.75. The name sounds exotic. It is one button on a calculator.
FEDIAF still uses 0.75, “which is also recommended by NRC.” It also flags that some researchers prefer 0.67, which tracks body surface more closely, and that the accuracy of 0.75 in dogs “has been questioned.”
From there you get resting energy requirement, or RER, what a dog burns doing nothing at all. Here is the equation, from the Merck Veterinary Manual:
RER (kcal/day) = 70 × (bodyweight in kg)^0.75
Try it on a 20 kg dog. 20^0.75 is 9.46, so resting needs come to about 662 calories a day. That is the floor, not the feeding amount.
Merck lists a shortcut too, 30 × bodyweight + 70, “restricted to animals weighing > 2 kg and < 45 kg”. We would skip it. AAHA’s 2014 guidelines warn that it “will overestimate the caloric needs of patients weighing either <2 kg or >25 kg.” We ran both equations ourselves. The shortcut comes out about 5% high at 25 kg and 14% high at 40 kg.
The most complete published tables
FEDIAF’s Annex 7.2 has the fullest set we have found anywhere, and it sorts dogs two different ways. First by age. The middle column is calories per kg of metabolic bodyweight, with the published range in brackets.
| Age | kcal/kg BW^0.75 |
|---|---|
| 1–2 years | 130 (125–140) |
| 3–7 years | 110 (95–130) |
| Over 7 years | 95 (80–120) |
Then by activity:
| Activity level | kcal/kg BW^0.75 |
|---|---|
| Low, under 1 h/day (walking on the lead) | 95 |
| Moderate, 1–3 h/day, low impact | 110 |
| Moderate, 1–3 h/day, high impact | 125 |
| High, 3–6 h/day (working dogs, e.g. sheep dogs) | 150–175 |
| High under extreme conditions (racing sled dogs, 168 km/day in extreme cold) | 860–1,240 |
| Obese-prone adults | 90 or less |
| Great Danes | 200 (200–250) |
| Newfoundlands | 105 (80–132) |
Two rows deserve a second look. The obesity-prone row sits at 90 or less, below even the lowest activity tier. That is the row most owners of a food-obsessed dog actually need. And FEDIAF names breed exceptions. A Great Dane is listed at roughly double a Newfoundland of the same metabolic weight.
FEDIAF is blunt about what all of it is worth. The numbers “should only be used as starting points, and the owner has to adapt the amount when the animal tend to lose or gain weight.”
Why the guidelines run high
This is the most useful line in the annex, and it is FEDIAF talking about its own field: “Recommendations for MER may overestimate energy needs by 10 to 60%.”
MER is maintenance energy requirement: resting needs plus the moving around a dog does in an ordinary day. Overestimate it by that much and you are feeding a dog that never gets walked as though it did.
FEDIAF says as much. The tables “often include a reasonable amount for activity, whereas approximately 19% of the owners never play with their dogs, and 22% let their dogs out for exercise for less than three hours a week.”
It also explains why its own headline number is lower than NRC’s. NRC builds on 130, “which is the average energy intake observed in laboratory kennel dogs or active pet dogs.” FEDIAF uses 110, “typical for dogs with 1-3 hours of low impact activity or less than 1 hour high impact activity.” And it points out that pet dogs in one-dog homes, walked under an hour a day, ate “an average energy intake ranging from 94 to 105 kcal/kg BW^0.75.”
That is the whole disagreement in three numbers. 130 is a kennel-and-athlete figure. 110 is a well-walked pet. 95 is a dog that gets round the block. They are not rival guesses about the same animal.
FEDIAF’s advice follows from that: “To avoid overfeeding and the risk of obesity, it may be better to start from a lower calculated MER and add as needed to maintain optimal body weight.”
What the other bodies publish
| Source | Category | Coefficient |
|---|---|---|
| Merck | Intact adult | 1.8 × RER (≈126) |
| Merck | Neutered adult | 1.6 × RER (≈112) |
| Merck | Prone to obesity | 1.4 × RER (≈98) |
| Pet Nutrition Alliance | Inactive / overweight-prone | 1.2–1.4 × RER |
| WSAVA (NRC) | Active adult | 130 |
| WSAVA (NRC) | Inactive adult | 95 |
Look at the shape of that, not just the numbers. Merck sorts adult dogs by neuter status and gives no activity tiers. FEDIAF sorts by activity and age and gives no neuter factor. A calculator that asks you for both is stitching two models together, and it ought to say so.
One 20 kg dog, eleven ways
| Method | kcal/day |
|---|---|
| FEDIAF, Great Dane row, 200 | 1,891 |
| FEDIAF, high activity working, 150–175 | 1,419–1,655 |
| FEDIAF age 1–2 y, and NRC active, 130 | 1,229 |
| FEDIAF moderate high-impact, 125 | 1,182 |
| Merck intact, 1.8 × RER | 1,192 |
| FEDIAF moderate low-impact and age 3–7 y, 110 | 1,040 |
| Merck neutered, 1.6 × RER | 1,059 |
| Merck obesity-prone, 1.4 × RER | 927 |
| FEDIAF low activity, age over 7, NRC inactive, 95 | 898 |
| FEDIAF obese-prone adults, ≤90 | ≤851 |
| Pedrinelli 2019, measured pet dogs, 86.1 | 814 |
Merck adds that any given dog “may require as much as 30% more or less” than the number you calculate. The Pet Nutrition Alliance says 50%. Read that again. The gap between two dogs is wider than any adjustment these tables ask you to make. It is the single most important line on this page.
What measuring real dogs shows
Bermingham and colleagues (2014) pooled 70 treatment groups covering 713 dogs. Sorted by how the dogs lived, in calories per kg of metabolic bodyweight: racing 202.9, working 188.6, hunting 164.8, pet 141.0, kennel 137.7. Only 23% of the groups were pet dogs. Pedrinelli’s 165 weight-stable pet dogs measured 86.1.
Two findings are worth carrying with you. Activity level was only a trend across the whole dataset (P = 0.09), though it held up among pet dogs on their own. And the best-fit exponent was not 0.75. It came out at 0.93 across all dogs and 0.97 in pet dogs, which is near enough a straight line with bodyweight. Every table above uses 0.75, and FEDIAF itself grants that the exponent “has been questioned.”
Age: three positions that do not agree
FEDIAF publishes the age tiers above. It says dogs over seven “may need 10-15% less energy than at three to seven years.” It calls age “the single most-important factor influencing MER of most household dogs.” It also warns that seven is a convention rather than a biological line: “Most of the assessed scientific work uses the age of seven years as a cut-off point, but this should not be regarded as a general rule.”
Set against that:
- Bermingham’s review found “the age of the dog had no effect on maintenance energy requirements.” Old adults actually came out slightly higher, at P = 0.99.
- The “20% less for seniors” figure you see everywhere traces back to Harper (1998). That paper says the decline “is assumed”, by analogy with humans. FEDIAF’s own number is 10–15%.
- FEDIAF’s separate statement on senior dogs says flatly: “At present there are no experimental data dealing with energy or nutrient requirements for older dogs.” It adds that needs can go up with “hormonal malfunctions … or in some cancers.”
So FEDIAF prints age tiers in its guidelines while its own advisory board says nobody has measured what older dogs need. That is not a gotcha. The tiers come from watching what dogs eat, not from controlled requirement studies, and both things can be true at once. But it does mean the age tier is softer than a tidy table makes it look. Trim a little as a dog ages, then let body condition decide the rest.
Breed
For most dogs, breed is a stand-in for adult weight. Once you know the weight, the breed name adds nothing. Bermingham found a breed-size effect on total calories that “disappeared when size was factored in.”
FEDIAF names exceptions, though, and they are big ones. Great Danes are listed at 200 (200–250) and Newfoundlands at 105 (80–132). FEDIAF’s explanation: “some breeds such as Newfoundland dogs and huskies have relatively lower energy requirements, while Great Danes have a MER above the average.” It puts that down to temperament and activity as well as coat insulation, and notes that NRC flags Newfoundlands, Great Danes and terriers as “breeds with energy requirements outlying the predictive range.”
There is a genetic exception too. Some dogs carry a deletion in the POMC gene, which helps control appetite. Raffan and colleagues (2016) found it at 12% allele frequency in Labradors (roughly one gene copy in eight) and in flat-coated retrievers, linked to more food motivation and higher bodyweight. Dittmann and colleagues (2024) then measured resting energy burn “approximately 25% lower” in affected dogs.
Both findings are real. But that measurement came from 19 flat-coated retrievers, all carrying two copies of the deletion, and no owner knows their own dog’s genotype. It explains why some Labradors are so hard to keep lean. It is not something you can type into a calculator.
Neutering
Merck’s 1.6 against 1.8 works out at 11% less for a neutered adult. It is a table entry with no measurement cited behind it.
Bermingham measured neutered dogs at 146.4 ± 21.5 against intact dogs at 195.7 ± 23.4, which implies about 25%. That rests on thin ground, though. Only two treatment groups were all-neutered, against seven all-intact. Sixty-one of the 70 groups did not record neuter status at all. And the authors say the difference “was not evident in either working dogs or pet dogs.” FEDIAF publishes no neuter factor whatsoever.
So adjust modestly, and do not treat 25% as settled. A different question (what neutering does to a dog’s skeleton and final size) is covered in does neutering affect how big my dog gets. The two get confused constantly.
Current weight or target weight
Target weight. AAHA 2021 says to “base feeding calculations on current weight if ideal or underweight or on ideal BW if overweight or obese in order to provide energy to current lean mass.” In plain terms, you feed the muscle a dog has, not the fat. For active weight loss, “base these calculations on ideal weight.” AAHA 2014 writes it straight into the equation: “RER in kcal/day = 70 × (ideal BW kg)^0.75.”
Get this backwards and you feed an overweight dog exactly enough to stay overweight. It is a bigger error than picking the wrong multiplier.
Weight loss
The guidance disagrees with itself across editions, which is worth knowing before you trust any single figure.
- AAHA 2014: “feeding 80% of ideal-weight RER is effective and well tolerated” (about 56 calories per kg of metabolic bodyweight), aiming at 1–2% of bodyweight a week.
- AAHA 2021: puts weight loss at 1.0 × RER, and reports “mean caloric intake for weight loss over a 12 wk period is 63 ± 10.2 kcal/kg0.75 in dogs.” No rate target given.
- Flanagan and colleagues (2017), 926 dogs, allocated “60 to 80 kcal per kg0.75 of TBW … depending upon sex and neuter status”: intact males 80, neutered males and intact females 70, neutered females 60.
On the rate, that biggest study is the corrective. It achieved “0.9 ± 0.45% of initial body weight per week”, and calls 1–2% merely “a frequently suggested target.” If somebody promised you 1–2%, the largest dataset available did not get there.
Weight loss is also where a vet earns their fee. A dog that will not lose weight on a controlled ration needs hypothyroidism and Cushing’s disease ruled out. Both make weight loss harder, and neither responds to a smaller bowl.
Cold and housing move this more than you would think
FEDIAF’s section on keeping warm has numbers we have not seen quantified anywhere else. “When kept outside in winter, dogs may need 10 to 90% more calories than during summer.”
Once a dog is outside its comfortable temperature range, needs shift “by 2-5 kcal (8-21 kJ) per kg^0.75 for every degree centigrade.” FEDIAF puts that comfortable range at 15–20°C for long-haired breeds, 20–25°C for short-haired ones, and as low as 10–15°C for Alaskan Huskies.
Housing counts too. Dogs kept alone “with little opportunity to move” may need as little as 70. Dogs kennelled together, playing off each other, can go past 144.
So a short-coated dog living outdoors through a cold winter and a long-coated dog on a sofa are not the same sum. None of the activity tiers capture it.
Turning calories into food
AAFCO requires calorie content “expressed as kilocalories per kilogram of food as fed and as kilocalories per familiar unit (e.g. per can, per cup or per biscuit).” Look “under a heading titled ‘Calorie Content.’” Divide your daily target by the calories per cup and you have the amount to feed.
Two caveats. In the US, adoption is state by state. And the figure is often calculated rather than measured in a lab.
Count the treats. A large dental chew can be a tenth of a small dog’s daily allowance. Treats are where carefully built feeding plans quietly fall apart.
The practical version
Our dog calorie calculator runs every method on this page at once and shows you the span rather than picking a winner. If you would rather do it by hand:
- Take bodyweight in kg to the power 0.75. Use target weight if the dog is overweight.
- Multiply by 95 if the dog is walked under an hour a day, 110 for one to three hours, 90 or less if it gains weight easily.
- Start at the low end. That is FEDIAF’s own advice, because the tables run high for a lot of dogs.
- Divide by the calories per cup. Subtract the treats.
- Weigh monthly, feel the ribs, adjust by 10% at a time.
Step five is the one that actually works. Every source above says the same thing in different words. The sum is where you start, and the dog tells you whether you got it right. The hands-on method is in how to tell if your puppy is overweight, and it works just as well on adults.