Resting need, scaled by the three-quarter power, then activity
Daily calories come in two steps. First the resting energy requirement (RER) from body weight, then a multiplier for how active and how altered the dog is.
The 0.75 exponent is Kleiber's law: metabolic rate scales to about the three-quarter power of body mass. That is why you cannot use a flat kcal-per-kilo number across sizes.
Pick the activity factor
| Dog | Factor × RER |
|---|---|
| Neutered adult, typical | 1.6 |
| Intact adult | 1.8 |
| Overweight, on a diet | 1.0 – 1.2 |
| Senior, low activity | 1.2 – 1.4 |
| Very active / working | 2.0 – 5.0 |
| Puppy (0 – 4 months) | 3.0 |
| Puppy (4 months – adult) | 2.0 |
A neutered, moderately active dog is the common case at 1.6. Working sled and field dogs sit far higher.
Resting need at a glance
| Weight | RER (kcal/day) | ×1.6 (typical) |
|---|---|---|
| 5 kg | 234 | 374 |
| 10 kg | 398 | 637 |
| 20 kg | 659 | 1,054 |
| 30 kg | 886 | 1,418 |
| 40 kg | 1,099 | 1,758 |
- Use the ideal weight. For an overweight dog, run the formula on the target weight, not the scale reading, then trim to 80 percent for gradual loss.
- It is a starting point. Real needs vary by roughly plus or minus 50 percent between individuals. Watch the body condition and adjust portions over weeks, not days.
Common questions
How many calories does my dog need a day?
Start from resting need, 70 times body weight in kilograms to the power 0.75, then multiply by an activity factor. A neutered, moderately active 20 kg dog needs roughly 900 to 1,000 kcal a day. Feed to your dog's ideal weight, not its current weight.
Why not just multiply weight by a flat number?
Because metabolism does not scale straight with weight. A 5 kg dog burns about 47 kcal per kilo of body weight, while a 40 kg dog burns only about 32. The 0.75 exponent in the resting formula captures that, so small dogs get proportionally more.
How much less should a neutered dog eat?
About 25 to 30 percent less than an intact dog of the same weight and activity. Neutering lowers metabolic rate and raises appetite, which is why weight gain after the procedure is so common.
