3-Step Guide to Calculate Dry Matter Basis in Pet Food
Have you ever looked at a can of wet food and wondered why it seems to contain much less protein than dry kibble? A dry food might show 30% protein, while a wet food shows only 10% protein. At first glance, it looks like the dry food contains three times as much protein—but that's not necessarily true.
The reason? Water.
Wet and dry pet foods contain very different amounts of moisture, which makes comparing the numbers on their labels tricky. That's where Dry Matter Basis (DMB) comes in.
What Is Dry Matter Basis?
Dry Matter Basis is a way of looking at the nutrients in pet food without counting the water. Think of pet food as having two basic parts: Water + Dry Matter
Dry matter is everything left after the water is removed, including protein, fat, carbohydrates, fiber, vitamins, and minerals. Dry kibble typically contains relatively little moisture, while canned and other wet foods contain much more. Because the percentages on a pet food label include this water, wet food naturally appears to have lower percentages of protein and fat. Dry Matter Basis removes that difference and makes it easier to compare foods fairly.
Why Should Pet Parents Understand Dry Matter Basis?
DMB is especially useful when you're comparing:
- Wet food and dry food
- Two wet foods with different moisture levels
- Canned food and pouches
- Kibble and freeze-dried food
For example, seeing 10% protein on a canned cat food doesn't mean the food is necessarily low in protein. If most of that food is water, protein makes up a much larger percentage of what's left after the moisture is removed. That's why comparing the Guaranteed Analysis numbers alone doesn't always give you the full picture.
Dry Matter Basis Calculation
You don't need to be a nutritionist to calculate DMB. All you need are two numbers from the pet food label: moisture and the nutrient you want to compare.
Let's use a wet food containing:
Moisture: 78%
Crude Protein: 10%
Step 1: Find the Moisture
Look at the Guaranteed Analysis on the package and find Moisture.
In our example, it's 78%.
Step 2: Find the Dry Matter
Simply subtract the moisture from 100.
100% − 78% = 22% dry matter
That means approximately 22% of the food remains when water is excluded.
Step 3: Convert the Nutrient
Now compare the protein with the dry portion of the food.
10 ÷ 22 × 100 = approximately 45% protein on a Dry Matter Basis
That's the only calculation you need.
The wet food that appeared to contain just 10% protein actually contains approximately 45% protein when expressed on a Dry Matter Basis.
Does Higher Dry Matter Protein Mean Better Food?
Not necessarily. Dry Matter Basis tells you the concentration of a nutrient, but it doesn't tell you the overall quality of the food. A food with more protein isn't automatically better for every dog or cat.
A pet's nutritional needs can vary depending on its:
Species • Age • Life stage • Activity level • Health • Overall diet
The quality and digestibility of ingredients, calorie content, fatty acid profile, vitamins, minerals, and overall nutritional balance also matter.
Think of DMB as a comparison tool, not a pet food rating system.
Guaranteed Analysis vs. Actual Nutrient Content
There's one more thing to keep in mind when using numbers from a pet food label.
Guaranteed Analysis commonly lists values such as:
Crude Protein – Minimum
Crude Fat – Minimum
Crude Fiber – Maximum
Moisture – Maximum
These are guarantees rather than the exact amount found in every serving.
For example, "Crude Protein 10% min." means the food contains at least that amount—it may actually contain more. Therefore, a DMB calculation using the Guaranteed Analysis should be considered an estimate. If you need a more precise comparison, you can ask the pet food manufacturer for its typical nutrient analysis.