Caloric density straight from the label
Copy crude protein, fat, moisture, fiber and ash from the package and the tool first works out the estimated carbohydrate share as 100 minus those five values, then multiplies the three macronutrients by energy factors to give kcal per gram and per 100 grams. Add a serving size in ounces and you also get the energy in that serving, converted at 28.3495 grams per ounce. Dry and canned versions of the same recipe differ widely per gram because of moisture.
Why the factors are a choice
The guaranteed analysis format itself follows the labeling framework used by AAFCO. Energy factors, however, differ between sources, so you can pick the modified Atwater factors common on pet food labels (protein 3.5, fat 8.5, carbohydrate 3.5) or standard Atwater factors (4, 9, 4), or type your own. The applied factors and the full formula are printed with the result. Information here is current as of October 2026.
This is a label-based estimate and will differ from measured metabolizable energy. Daily feeding amounts and weight loss targets are not calculated here. This tool is for reference only and does not replace veterinary care. Contact your veterinarian right away if you notice symptoms or suspect a problem.
Frequently asked questions
Pick whichever lands closest to the kcal figure printed on the package, or type the factors your veterinarian or the maker supplied.
Labels rarely print it, so the tool estimates it as 100 minus the other five values and shows that estimated share with the result.
No. It only gives caloric density. Daily energy depends on body weight and activity, so set that with your veterinarian.