Pet Food Math Cheat Sheet
Are you feeding a diet high in carbohydrates?
Steve Brown pet food formulator states the gold standard for the food calories breakdown would be:
Note that the percentage of calories is not the same as the "guaranteed analysis" %. To determine the percentage of calories we have created the Pet Food Math Cheat Sheet which you can use to analyze and compare any type of pet food. Dry kibble, canned food, baked kibble, freeze-dried, raw, etc.
Cheat sheet food tabs 1-8 are for pet pet quality foods. Pet foods are considered less digestible than human-quality foods so calories (kcal) for pet foods are calculated: (3.5, 8.5, 3.5)
Protein 3.5 calories (kcal) per gram (g)
Fat 8.5 calories (kcal) per gram (g)
Carbs 3.5 calories (kcal) per gram (g)
Cheat sheet food tabs 9-10 are for human-grade pet foods. Very few companies meet this standard. “Human-quality foods are generally more digestible than pet quality foods” so calories (kcal) for human foods are calculated: (4, 9, 4)
Protein 4 calories (kcal) per gram (g)
Fat 9 calories (kcal) per gram (g)
Carbs 4 calories (kcal) per gram (g)
Enter the information from the "Guaranteed Analysis" and the "Calorie Content" on the food label and the cheat sheet will do the math so you can compare any type of food.
Use the Pet Food Math Cheat Sheet to determine:
Grams (g) of protein, fat, and carbs per 1,000 calories
Cups per package
Cost per cup
Cost per 1,000 calories
Percentage of Calories from:
With dry food determining the cost to feed per day and how long a bag of dry food will last can be a bit complicated because dry foods have differing densities and weights. The typical dry food is close to 4 oz per cup and has about 4 cups per pound. But foods can vary widely. One food can have close to 3 oz a cup (5 ¼ cups/lb) and another about 5 ¾ oz a cup (2 ¾ cups/lb). With the Pet Food Math Cheat Sheet you can determine the ounces per cup and cups per pound of food using the calorie content of the food. The Pet Food Math Cheat Sheet is a Microsoft Excel spreadsheet. You can download and use Microsoft Excel for free. https://www.office.com/
The spreadsheet can also be opened and used with other spreadsheet programs like Google Sheets. https://www.google.com/sheets/about/
Pet Food Science
All pet food consists of protein, fat, fiber, moisture, ash, and carbohydrates.
“The total of these components equals 100%. Ash is what’s leftover if one cooks the food at very high temperatures; it is generally the mineral content of the food. Fiber is the part of the plant material that the dog cannot digest; it’s considered to be a carbohydrate.” 
Protein, fat, and digestible carbohydrates are the key ingredients in pet foods and are referred to as “macronutrients” and these three nutrients provide the calories (energy).
Dog and cat foods in the USA are required to list a “Guaranteed Analysis” of the nutrient content of the food. The guaranteed analysis lists protein, fat, fiber, and moisture percentages as minimums or maximums and is not meant to provide exact percentages. The actual amounts can vary a little or a lot from the guaranteed analysis so the amount of kcal (calories) per gram will be less then reported for kcal/kg (calories / 2.2 lbs). Pet food manufactures are not required to list “ash” or “carbohydrates” in the food but some will provide this information if asked or have it listed on their website. To determine the minimums and maximum percentages of nutrients in the food manufacturers will run a proximate analysis of the food to get the batch average of a food.
The calorie content of a food is dependent on the amounts of protein, fat, and carbohydrates in the food. Carbohydrates are refered to as “nitrogen-free extract” or “NFE”. Carbohydrates are determined simply by subtracting the average of each of the other components (protein, fat, fiber, moisture, and ash) from 100.
Calorie content is not a guarantee but rather an average that can be calculated from the proximate analysis data used for setting guarantees.
In Europe rather than use the “guaranteed analysis” which only provides minimums and maximums, they list a “Typical Analyses” which reports the “typical” averages for the food. These percentages are generally much closer to the actual food composition than what is reported with the guaranteed analysis. A typical analyses following European guidelines includes protein, fat, fiber, ash, and moisture if more than 14%.
To determine the minimums and maximum percentages of nutrients in the food manufacturers will run a proximate analysis of the food to get the batch average of a food.
Column 1 “GA” Guaranteed Analysis on the food label
Column 2 “DM” Dry Matter basis after all moisture removed. (water)
Column 3 “kcal g” Number of calories per gram of protein, fat, and fiber in pet food. (Human food has slightly higher calories.)
Column 4 “kcal g (P,F,C) Number of calories per gram of food for protein, fat, and carbs.
Column 5 “% kcal” Percentage of calories from protein, fat, and carbs.
Column 6 “g-1000 kcal” Number of grams of protein, fat, and carbs per 1,000 calories.
Column 7 “kcal – 1000 kcal” Number of calories from protein, fat, and carbs per 1,000 calories.
Column 8 “% kcal” Percentage of calories from protein, fat, and carbs in food.
kcal/kg Calories per kg. A kg is equal to 2.2 lbs. There are 1000 grams in a kg. (Kilogram)
kcal kcal is the same as a calorie in human foods.
Protein Protein can come from animal or plant based foods. Protein is made up of amino acids. Animal based protein is generally of higher quality protein and contains balanced amino acids.
Fat Fat provides the most calories and energy.
Fiber Fiber is classified as a carbohydrate but it is not digestible. (provides no calories/energy)
Ash Ash is what is left over after heating food at a very high temperature; generally the mineral content.
Carbs Carbohydrates supply necessary starches to make dry kibble. Dogs and cats have no requirement for carbohydrates. They can derive all the energy they need from protein and fat.