Most guides to feeding raw tell you to feed 2-3% of your dog's body weight per day.
It's simple. It's easy to remember. And for some dogs, it's close to right. For others, it's badly off.
A 25kg neutered Labrador with low activity does not need the same amount of food as a 25kg intact working Spaniel. They weigh the same, but their energy requirements are completely different.
If you've ever weighed out 2.5% and watched your dog either leave food in the bowl or start circling back for seconds within an hour, you've already found this out yourself.
Here's how to work out the right amount for your dog, and why the simple rule works some of the time.
Why Percentage-Based Feeding Is Imprecise
The "2-3% of body weight" rule has been around for decades. It persists because it's easy to remember and roughly works for an average adult dog at an average activity level.
The problem is that most dogs aren't average.
A percentage-based calculation ignores activity level (a couch dog vs a field dog), neuter status (intact dogs burn more energy), age (puppies need proportionally more, seniors need less), body condition (an overweight dog needs fewer calories, not a fixed percentage of a higher weight), and the caloric density of the food itself. Two raw foods with different formulations can have very different calorie counts per gram. Feeding 2.5% of body weight means nothing if you don't know how many calories are in each gram.
The result is that some dogs are overfed and some are underfed, even when owners follow the rule carefully.
The Variable Nobody Talks About: Caloric Density
Even if you calculate portions precisely, the accuracy depends on one thing most people overlook: the energy content of the food itself.
Different recipes have different caloric densities. A chicken-based formulation contains a different number of calories per gram than a beef-based one, or a fish-based one. The difference comes from the whole recipe, not just the protein source, but the effect is the same: the calorie count changes.
This creates a challenge for any brand offering multiple recipes. A calculator can account for different densities, but it has to know which recipe is in the box this month. Otherwise the portion is right for one recipe and approximate for the others.
Over weeks and months, these small variations can add up. Not dramatically, but enough to make precise weight management harder than it needs to be.
The alternative is one consistent recipe. With a single formulation, you never have to recalculate because something different arrived in the next box. The food stays the same, so the calculation has one less variable in it.
The variety that other brands achieve through recipe rotation, we put into one complete formula. Multiple proteins, organs, bone, and fish in a single blend. Dietary breadth in every meal, with the caloric density held constant.
How Veterinary Nutritionists Actually Calculate Portions
The method used in clinical veterinary practice is based on metabolic energy requirements. It's more precise because it accounts for the variables that percentage feeding ignores.
It works in two steps.
Step 1: Calculate Resting Energy Requirement (RER).
This is the amount of energy your dog needs just to exist. Breathing, circulating blood, maintaining body temperature. The formula is standardised across veterinary science. Resting energy is calculated from body weight raised to the power of 0.75, multiplied by a coefficient.
The 0.75 exponent accounts for the fact that metabolic rate doesn't scale linearly with body weight. A 40kg dog doesn't need twice the calories of a 20kg dog. Metabolic scaling is more nuanced than that.
Step 2: Adjust for your dog's life.
The RER is then multiplied by a factor that reflects your dog's actual circumstances. These factors have been established through decades of veterinary research.
Activity level makes the biggest difference. A low-activity neutered adult sits towards the bottom of the published range. A high-activity intact adult can need half as much again, or more, at the same weight. Where those figures come from, and why the sources disagree, is covered in Understanding Your Dog's Calorie Needs: RER and MER Explained. Working dogs sit at the top of the activity range, and the calculator handles them through the high-activity input.
Neuter status matters because intact dogs have higher metabolic rates. Age matters because puppies need 2-3 times adult energy for growth, while seniors need roughly 10% less as their metabolism slows. Body condition matters because an overweight dog needs a calorie reduction, not the same percentage of a higher body weight.
Once you have the adjusted energy requirement, you divide it by the caloric density of the food to get a daily portion in grams. Say a dog needs 700 calories a day and the food contains 1,500 kcal/kg, or 1.5 kcal/g: the daily portion is 700 divided by 1.5, which is around 465 g. That second number is a property of the recipe, which is why a calculator built for one food can be precise about the portion and a general rule cannot.
If that looks fiddly, it is. The calculator handles every step of this in 60 seconds.
Why the Percentage Changes With Size
A dog's energy needs do not rise in step with its weight. They rise more slowly. A dog twice the size of another needs more food, but not twice as much, which is why the calculation raises weight to a power rather than multiplying it directly.
That is why no single percentage holds across sizes. Hold activity, life stage and body condition constant, and a smaller dog needs more food relative to its body weight than a larger dog on the same food. The 2-3% rule takes part of that curve and states it as a flat range.
The practical effect is predictable. For otherwise comparable dogs on the same food, the percentage falls as body size rises. So a small dog whose portion works out well above 2.5% is not unusual, and a large dog whose portion falls below it is not being underfed. Size is not the only thing that changes the answer, but it changes it before activity, age, neuter status or body condition enter the calculation at all.
Everything else the rule ignores compounds that. An intact working Spaniel might need closer to 3.5% or 4%. A retired, overweight Labrador might need 2% or less. A growing puppy needs far more than any adult rule would suggest. The calculator captures all of this through the activity, age, neuter, and body condition inputs. The simple rule does not. Small breeds sit at the other end of the same problem, where a modest error in grams is a large error in proportion. Our Miniature Schnauzer guide covers what that means in practice.
So the right way to think about the 2-3% rule is this: a rough starting point, closest for a mid-sized adult dog, drifting further the further your dog sits from that middle. It is not a substitute for the actual calculation.
Puppies, Seniors, and Special Cases
Puppies need significantly more food relative to their body weight than adults. A puppy under 4 months old needs approximately three times their resting energy requirement. From 4 to 12 months, this drops to about twice. From 12 to 24 months, it settles to around 1.8 times before reaching adult levels.
This is why feeding a puppy based on a percentage of their current body weight is particularly risky. Their needs change rapidly as they grow, and getting it wrong during development can have lasting consequences.
Senior dogs (7 years and older) typically need about 10% fewer calories than adults at the same activity level. Their metabolism slows, and overfeeding contributes to weight gain that stresses ageing joints.
Dogs recovering from illness, and pregnant or nursing dogs, have specific energy requirements that fall outside standard ranges. If your dog is in either of these categories, consult your vet for guidance on portions.
Fine-Tuning Your Dog's Portion
The calculator gives you a precise starting point based on veterinary metabolic science. Every dog is an individual, so monitor your dog's weight and body condition over the first few weeks and adjust slightly if needed. Most dogs do well on the calculated portion from day one.
If your dog is gaining weight, reduce the portion slightly. If they're losing weight or seem hungrier than usual, increase it. Small adjustments of 10-15% are usually enough.
If your dog is already above their ideal body condition, Managing Your Dog's Weight on Raw Food covers how to check condition by hand, set the starting portion from where you're aiming rather than where you are, and review the result over months.
Calculate Your Dog's Portion
Our feeding calculator uses the method described in this article. Enter your dog's weight, age, activity level, body condition, and neuter status, and it returns a daily portion, recommended box size, and delivery frequency.
It takes about 60 seconds. No account required.