The Label Lie: Why Water Masks Nutrition
Guaranteed Analysis panels on pet food labels are required by law to show percentages "As Fed." This includes the weight of the water. Because canned food is mostly water, its protein percentage looks much lower than kibble, even if the canned food is actually more nutrient-dense. The Dry Matter Basis (DMB) calculation is the only way to compare these two formats fairly.
How the Calculation Works
Think of it as "dehydrating" the label in your mind. The formula works by calculating what percentage of the food remains once all the water is removed:
DRY MATTER % = (Nutrient % / (100 - Moisture %)) * 100
A consumer is comparing a premium Canned Food to a standard
Kibble.
- Canned Food: 10% Protein, 78% Moisture.
- Kibble: 26% Protein, 10% Moisture.
On the shelf, the kibble looks like it has 2.6x more protein. However, using DMB:
- Canned DMB: (10 / (100-78)) * 100 = 45.4% Protein.
- Kibble DMB: (26 / (100-10)) * 100 = 28.8% Protein.
The Reality: The canned food actually provides significantly more protein
per unit of dry matter.
Strategic Shopping Tips
For a healthy adult dog, many nutritionists look for at least 25-30% DMB protein. Working dogs or puppies may need 35%+. Always consult your vet for specific medical needs.
Yes. You can use this calculator for any nutrient listed in the Guaranteed Analysis (Fat, Fiber, Ash, etc.) to see its true concentration relative to the dry matter.