Dry Matter Basis Calculator For Pet Food

When comparing pet food, the reported guaranteed analysis must be converted to dry matter basis. Without making this conversion, you're essentially comparing apples to oranges and thereby drawing incorrect conclusions.

What is Dry Matter Basis?

Dry matter basis is a representation of nutrients (i.e. protein, fat, and fiber) which ignores the moisture content of the food. In other words, it's the amount of protein, fat, and fiber which would be reported if the product's moisture were completely removed.

The numbers reported on the guaranteed analysis panel of pet food packaging is commonly refereed to as the as fed basis percentages. We can use these numbers to calculate the dry matter basis percentages. By converting the as fed basis percentages to dry matter basis, we can make meaningful comparisons between products of various moisture contents (i.e. canned food vs. dry food).

Why is Dry Matter Basis Important?

Pet food products with high moisture often report protein percentages below 10%. It's almost impossible to find dry products with protein percentages below 15%. Does this mean that manufactures are including less protein in wet foods? Absolutely not, the difference lies in the moisture.

If one were to cook wet dog or cat food, the moisture percentage would decrease whereas the protein percentage would increase. In essence, comparing the nutrients of two products with different moisture percentages is very misleading.

Examples Of Dry Matter Basis

We've defined dry matter basis and discussed the importance of this representation, now let's learn how to convert as fed basis to dry matter basis. The conversion is very simple,

\frac{Quantity}{100 - Moisture}\times100

The "quantity" represents the as fed basis percentage of the value which you are trying to convert. The moisture is the percentage reported on the guaranteed analysis panel of the pet food package.

Let's run through a quick example to see how this works. I've randomly picked two products to compare.

  1. Blue Buffalo Wilderness Chicken Recipe For Senior Dogs (Dry Dog Food)
  2. Canidae Life Stages Lamb and Rice Formula (Wet Dog Food)
Guaranteed Analysis (as fed basis)
Blue Buffalo Product Canidae Product
Protein 30% 9%
Fat 12% 6%
Fiber 7% 1.5%
Moisture 10% 78%

From the table above, it may appear that the Blue Buffalo product has more protein. Let's compute the dry matter basis numbers to compare the two products.

Convert protein: from as fed basis to dry matter basis

Blue Buffalo Protein: \frac{30}{100 - 10}\times100 = 33.33%

Canidae Protein: \frac{9}{100 - 78}\times100 = 40.91%

Convert fat: from as fed basis to dry matter basis

Blue Buffalo Fat: \frac{12}{100 - 10}\times100 = 13.33%

Canidae Fat: \frac{6}{100 - 78}\times100 = 27.27%

Convert fiber: from as fed basis to dry matter basis

Blue Buffalo Fiber: \frac{7}{100 - 10}\times100 = 7.78%

Canidae Fiber: \frac{1.5}{100 - 78}\times100 = 6.82%

Convert Moisture (For Completeness): from as fed basis to dry matter basis

Blue Buffalo Moisture: \frac{10}{100 - 10}\times100 = 0%

Canidae Moisture: \frac{78}{100 - 78}\times100 = 0%

Guaranteed Analysis (dry matter basis)
Blue Buffalo Product Canidae Product
Protein 33.33% 40.91%
Fat 13.33% 27.27%
Fiber 7.78% 6.82%
Moisture 0% 0%

As we can see from the table, the Canidae wet food contains more protein, more fat, and less fiber. You can carry out these calculations for any two products, or you can use our widget (located at the top of this post) to quickly compute dry matter basis percentages.

If you'd like, you can search for pet food products in PawDiet's database. Our product pages include both the guaranteed analysis and dry matter basis values for both dog and cat food products.