You can estimate how much energy your dog uses at rest from one number you already know, and you can check whether the estimate is right with your hands. Most owners have been told how many scoops their dog gets. Very few have been told how many calories.
Why the number starts with calories
A portion in grams only means something once you know the food. The same dog needs fewer grams of an energy-dense food and more of a lighter one, so the honest way to state what a dog needs is in energy: kilocalories a day, usually just called calories. Grams come afterwards. If you want the practical answer first, How Much Raw Food Should I Feed My Dog covers it.
Feeding a percentage of body weight skips that step, and it makes a second error that matters more. It assumes a dog twice as heavy needs twice as much food.
It doesn't.
The resting number, and why size isn't simple
Vets start from resting energy requirement, or RER: roughly what a dog's body uses in a day at rest. The standard formula is:
RER (calories a day) = 70 × body weight in kg0.75
The 0.75 is the important part. Raising weight to that power means energy need grows more slowly than weight does, because smaller bodies use more energy per kilo than larger ones. The European pet food industry's nutritional guidelines make the same point: across dogs of very different sizes, energy needs do not rise in step with body weight.
You don't need to work it out by hand. As a guide, a 10 kg dog uses about 390 calories a day at rest, a 20 kg dog about 660 and a 30 kg dog about 900. Doubling the weight from 10 to 20 kg doesn't double the number.
Across a wider range the gap grows. A 30 kg dog is six times the weight of a 5 kg dog, but its resting need is only about 3.8 times higher: roughly 900 calories against 235. A rule that feeds in proportion to weight gets this wrong, and it gets it wrong in a predictable direction.
Calculated from RER = 70 × body weight in kg0.75.
Set a percentage rule so that it is right for a 15 kg dog, and it gives a 3 kg dog about a third less than its metabolism suggests and a 40 kg dog more than a quarter extra. Move the calibration point and the errors move with it, but they never disappear. That is the whole case for starting from calories rather than from weight.
From resting to daily: what moves the number
Resting need is the starting reference, not a day's food. Maintenance energy requirement, or MER, is the estimate of what your dog uses on an ordinary day. It is worked out from the same metabolic weight, with the things that change it layered on top. Four matter most.
Life stage. Puppies are fed for growth, which is a different and much larger calculation (see Raw Feeding for Puppies). At the other end, dogs over about seven may need 10 to 15 per cent less than in middle age, though the age at which that happens varies between dogs.
Activity. The biggest lever after weight. In the European guideline figures, a dog doing one to three hours a day of low-impact activity is allowed about a sixth more than a dog walked on the lead for under an hour.
Neuter status. Neutered dogs generally need less than intact ones, and veterinary references allow for it.
Body condition. A dog carrying extra weight is fed for the weight it should be. That changes the calculation more than most people expect, and it has its own section below.
The published figures also do not agree. For a neutered 20 kg adult, a widely used veterinary reference multiplies RER by 1.6, which gives about 1,060 calories. The European guidelines express the figure directly against metabolic weight rather than as a multiple of RER, and give about 900 calories for a dog with under an hour's activity a day, or about 1,040 for one doing one to three hours. Same dog, same exponent, answers nearly a fifth apart before anything is known about the dog itself.
That is not a flaw in either source. It is what an estimate looks like. The error also tends to run one way: the same guidelines note that maintenance recommendations may overestimate what dogs need by 10 to 60 per cent, partly because many household dogs are less active than the figures assume. Their advice is to start from a lower estimate and add food if the dog needs it.
When the dog needs to lose weight
For an overweight dog, the plan is built around the weight the dog should be, not the weight it is. A large international weight-loss study set each dog's daily energy allowance from an estimated target weight, then adjusted it as the dog responded.
This is where a sensible ration can look alarming. Take a dog that weighs 24 kg but should weigh 20. Measured against what a 24 kg dog uses at rest, a ration calculated for 20 kg looks short, because it was calculated for a smaller dog. That is the wrong comparison. The extra 4 kg is the fat the plan exists to remove, and a correct calculation measured against the wrong baseline produces a confident, specific and entirely wrong conclusion.
Managing Your Dog's Weight on Raw Food covers how to run a weight-loss plan day to day.
An estimate you check, not a number you obey
Every formula here describes a typical dog of a given size. Yours is a particular dog, and two dogs of the same weight can differ by as much as 30 per cent in what they need. No calculation removes that, however careful it is. Checking does.
The check is body condition. Run your hands along your dog's side: you should be able to feel the ribs under a light covering without pressing, and see a waist from above. Feeding guidelines recommend keeping dogs in the middle of the body condition scale for health and longevity.
If the ribs get harder to find over a few weeks, your dog needs a little less. If they start to show, a little more.
That is the reason to understand the method. The calorie figure is a statement about your dog: what a dog of its size, age, activity and condition is likely to need. Turning it into grams is a statement about the food, and depends on how much energy the food carries.
Protocol Raw Complete is one complete recipe, so there is one known food to convert into, and the calculator can turn your dog's calorie target into a daily portion properly. Raw Dog Food Calculator: How to Get Your Dog's Portion Right explains what it asks and why. After that, your dog tells you whether the estimate was right.