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If you want to calculate the daily caloric requirements of your dog, you need to understand that the figure is a result of various variables which we’ll discuss in detail here. I have also explained how you can calculate the daily caloric requirements of your dog.

## What are calories?

Calories are units of energy. In the context of nutrition, calories refer to the energy from the food and drinks consumed, and the energy they use in physical activity. The energy required by a dog is provided in the diet from protein, fat, and carbohydrates.

## How to determine caloric intake in dog food:

### Bomb calorimetry:

The most direct way to measure the energy value of food is by bomb calorimetry. This involves burning a known quantity of the food in a special instrument (a bomb calorimeter) and measuring the heat released. The energy content of the food can then be calculated from the heat released.

The problem with bomb calorimetry is that it only measures the energy available from the food once it has been digested and absorbed by the body. This may not be the same as the energy value of the food as eaten by the animal, because some of the energy in the food may be lost in feces or unavailable for absorption by the gut.

In addition, bomb calorimetry only measures the energy content of the food, not how well the animal can use that energy. For example, a food that is high in fat may have a high energy content but be low in digestibility, so the animal may not be able to use all of the energy in the food.

### Atwater factors:

The energy content of food can also be estimated using the Atwater factors. The Atwater factors are a set of values that are used to calculate the energy content of carbohydrates, proteins and fats.

To calculate the energy content of a food using the Atwater factors, you need to know the percentage of each nutrient in the food. For example, if a food contains 10% carbs, 20% protein and 30% fat, the energy content of the food would be:

• 4 x 10% = 0.4 kcal/g for carbohydrates
• 4 x 20% = 0.8 kcal/g for proteins
• 9 x 30% = 2.7 kcal/g for fat

Total energy content of the food = 0.4 + 0.8 + 2.7 = 4.1 kcal/g.

### Using the Maintenance Energy Requirement formula:

Another way to calculate the daily caloric requirements of your dog is to use the Maintenance Energy Requirement (MER) formula. The MER formula takes into account the dog’s body weight, body condition score, activity level and the climate in which they live.

To use the MER formula, you need to know the following:

• -Your dog’s body weight in kilograms (kg)
• -Your dog’s body condition score on a 3-point scale
• Signalment – neutered vs intact dog

I have described each of the above variables used to calculate MER in detail below but first, let’s look at factors that will influence how much energy your dog will need every day;

## Factors that influence the energy requirements of dogs:

There are several factors that influence the daily caloric requirements of dogs, including:

• -Size: The smaller the dog, the less energy they need.
• -Age: Puppies and young dogs need more calories than adults because they are growing. Senior dogs may need fewer calories than adult dogs because they are less active.
• -Activity level: Active dogs need more calories than sedentary dogs.
• -Temperature: Dogs need more calories in cold weather because they use more energy to keep warm.
• -Pregnancy and lactation: Pregnant and nursing dogs need more calories than non-pregnant dogs.
• -Disease: Dogs with certain diseases may need more or fewer calories than healthy dogs.

## Calculating daily caloric requirements (MER) of a dog using adjusted RER:

You can calculate the daily caloric requirements also known as the Maintenance energy requirement of a dog using their resting energy requirement (RER) and their signalment, body condition score (BCS), and activity level.

### What is MER?

The Maintenance Energy Requirement (MER) is the amount of energy needed by a dog to maintain its weight and body condition. The MER includes the energy needed for all of the dog’s normal body functions, including digestion, metabolism, respiration, circulation, temperature regulation, cell growth and repair, and physical activity.

## What is RER?

The Resting Energy Requirement (RER) is the amount of energy needed by a dog to maintain its body functions at rest. The RER includes the energy needed for the dog’s heart to beat, lungs to breathe, kidneys to filter blood, and brain and other organs to function.

The activity level of a dog is used to estimate its energy requirements above their RER. The activity level is a measure of how much physical activity a dog gets in a day. It can be estimated from the dog’s weight, body condition, and lifestyle.

### How is RER Calculated:

For medium-size dogs, use this more accurate formula;

• 30 x (body weight in kilograms) + 70 = RER for medium-sized dogs and cats

For small and large-breed dogs, use this formula;

• 70 x body weight in kilograms to the ¾ power = RER for small/large dogs and cats

### RER Calculators:

There are online RER calculators. Below are some good ones I found online;

### How do you calculate MER?

There are a number of different formulas that can be used to estimate the MER of a dog. The most common formula is the Resting Energy Requirement (RER), which is based on the dog’s body weight, body condition, and activity level.

### This is the formula: MER=RER*Signalment*Activity level*BCS

RER which stands for Resting Energy Requirement is calculated using the following formula:

RER = 70 x (body weight in kg)^0.75

For example, a 10 kg dog would have an RER of:

70 x (10 kg)^0.75 = 175 kcal/day

### How to calculate RER:

To calculate the RER, you need to know the dog’s weight in kilograms. You can convert pounds to kilograms by dividing the weight in pounds by 2.2.

For example, a 10 kg dog would have an RER of:

70 x (10 kg)^0.75 = 175 kcal/day

The activity level factor is used to adjust the RER for dogs that are more or less active than average. The activity level factor is usually expressed as a number between 1 and 2. For example, a dog that is twice as active as an average dog would have an activity level factor of 2.

### Signalment:

The signalment factor is used to adjust the RER for different breeds of dogs. Smaller breeds of dogs have a higher metabolic rate than larger breeds, so they need more calories per kg of body weight.

The signalment factor is usually expressed as a number between 1.6 and 1.8 in dogs and 1.2 to 1.4 in cats. For example, an intact/non-neutered adult dog with an RER of 175 kcal/day would have a signalment factor of 1.8, which would give it a MER of:

175 kcal/day x 1.8 = 315 kcal/day

### Activity level:

Dog that regularly exercises requires much more energy daily compared to those that are inactive.

For the MER formula, the following classifications have been developed with each activity level assigned a factor score;

• Seldom or never active (e.g. pet dog that is mostly inactive indoors) = 1
• Somewhat active activity (e.g. pet dog that goes for a daily walk) = 1.2
• Active (e.g. working dog that does strenuous exercise 4-5 times per week) = 1.4
• Very active (e.g. sled dog that pulls a heavy load every day) = 1.6

### Body Condition Score(BCS):

The body condition score (BCS) is a way of estimating the amount of fat on a dog’s body a numerical score from 0.8 to 1.2. Fat or obese dogs don’t need a lot of energy but underweight dogs require more caloric intake.

To represent this in an equation that would make MER calculations easier, the following scores have been assigned to each activity level;

• Underweight gets a factor of 1.2
• Ideal weight gets a factor of 1
• Overweight or obese get a factor of 0.8

## Putting all these together to calculate the MER:

Again the formula for MER is;

MER = RER x Signalment Factor x Activity Level Factor x Body Condition Score (BCS)

For a 10 kg, adult, pet dog that is mostly inactive indoors and has an ideal body condition score, the calculation would be:

10 kg x 70 = 700

700 kcal/day x 1.8 (Signalment Factor for an adult pet dog) = 1,260

1,260 kcal/day x 1 (Activity Level Factor for a mostly inactive dog) = 1,260

1,260 kcal/day x 1 (Body Condition Score Factor for an ideal weight dog) = 1,260

Therefore, the MER for this dog would be 1,260 kcal/day.

To calculate the daily caloric intake for a dog, you will need to know the MER. Once you have the MER, you can then add in the calories needed for physical activity and growth (if applicable). For example, a 10 kg, adult, pet dog that is mostly inactive and has an ideal body condition score would need 1,260 kcal/day.

## Daily Calories to Achieve Weight Loss

If you want to manage your dog’s weight, you need to reduce their daily caloric intake by giving your pet a starting diet that is 80% of the dog’s RER.

## Video Guide on How to Calculate Dog Food Caloric Intake Daily:

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