Multi-Dog Food Splitter
Split one bag of food correctly between several dogs of different sizes, and see how long the bag lasts.
Total for the household
563 grams per day
| Dog | kcal/day | Grams/day | Share of bag |
|---|---|---|---|
| Dog 1 | 1,436 | 410 | 72.9% |
| Dog 2 | 533 | 152 | 27.1% |
- Total daily calories
- 1,969 kcal
- A bag lasts
- 21 days
- Bags per month
- 1.43
Feed each dog separately, in its own bowl and ideally its own space. Free feeding from one bowl means the fastest eater takes the largest share, which is how one dog in a household ends up overweight and another underweight on the same "correct" total.
How this is calculated
Each dog's requirement is calculated separately, then summed. The share of the bag each dog takes is its share of the household's total calories, which is not the same as its share of the household's total body weight.
for each dog:
MER = 70 × (kg^0.75) × life stage factor
grams = (MER ÷ food kcal per kg) × 1000
household total = sum of all dogs
bag days = (bag kg × 1000) ÷ total grams per day Why not just split by weight
A 30 kg dog weighs 3.75 times as much as an 8 kg dog but needs only about 2.7 times the food, because metabolic rate scales to the three-quarter power of body weight. Splitting by body weight would overfeed the large dog and starve the small one; splitting evenly does the reverse, and much more severely.
Worked example
A 30 kg neutered adult needs about 1,435 kcal and an 8 kg neutered adult about 533 kcal, a household total of 1,968 kcal. On a 3,500 kcal/kg food that is 410 g and 152 g respectively, 562 g a day in total. The big dog takes 73% of the bag, not 79% as body weight alone would suggest, and a 12 kg bag lasts about 21 days.
Sources
Feeding a multi-dog household
Weigh each dog's portion separately and feed in separate places. Lift bowls after fifteen minutes whether or not they are empty, so nobody grazes on someone else's ration. If one dog finishes far faster than the others, a slow-feeder bowl evens the timing out and reduces the pressure to guard.
Weigh the dogs monthly. In a multi-dog home a slow drift in either direction is much harder to notice by eye, because you are comparing them to each other rather than to how they looked six months ago.
Common questions
How do I split food between dogs of different sizes?
By calories, not by halves. Energy needs scale to body weight to the power of 0.75, so a 30 kg dog needs about 2.7 times what an 8 kg dog needs, not 3.75 times. Splitting a bag evenly overfeeds the small dog badly and underfeeds the large one.
Can I feed all my dogs from one bowl?
No. The fastest eater takes the largest share regardless of what it needs. This is the standard way one dog in a household becomes overweight while another stays thin on a total that looks correct.
How far apart should dogs be fed?
Far enough that no dog can reach another bowl before finishing its own. Separate rooms or crates are the reliable option. Guarding behavior between dogs that otherwise get along is very often just proximity at mealtimes.
Can dogs of different ages share the same food?
Adults can generally share an adult food. Puppies need a growth diet, and large-breed puppies need one formulated for large-breed growth because the calcium level matters for joint development. A senior with kidney or heart disease on a prescription diet must not share either.
How long will one bag last my dogs?
Divide the bag energy by the household daily total. Two dogs needing 1,300 kcal a day between them will empty a 12 kg bag of 3,500 kcal/kg food in about 32 days. Buy a bag size that finishes within about six weeks, since fats oxidize once it is open.