What is Dry Matter Basis (DMB) and why is it so important?

Dry Matter Basis (DMB) is the universal veterinary method for evaluating pet nutrition. By stripping out all water content mathematically, DMB lets you compare the true nutritional punch of canned food, dry kibble, raw diets, and freeze-dried patties on an exact apples-to-apples basis.

How do you calculate pet food carbohydrates if they are not listed on the bag?

Pet food companies are not required by law to print carbohydrate percentages on guaranteed analysis panels. Nutritionists use the Nitrogen-Free Extract (NFE) formula: subtract protein, fat, fiber, moisture, and ash from 100%. The remaining portion represents total carbohydrates.

What is a healthy carbohydrate percentage on a dry matter basis?

Cats are obligate carnivores whose bodies are designed for protein and fats; they thrive best on diets with less than 10% to 12% DMB carbohydrates (especially diabetic cats). Dogs are adaptive omnivore-carnivores that do well on moderate carbohydrates, generally between 20% and 40% DMB.

General & Conversions • nutritionVerified Formula

Pet Food Dry Matter & Carbohydrate Calculator

Q: Why can’t you compare wet food and dry food directly from the packaging label?

Canned wet pet foods contain between 75% and 82% water, whereas dry kibble contains only 8% to 10% water. Because water dilutes the visible percentages on the label, a canned food displaying "10% protein" actually packs ~45% protein once water is removed—often surpassing a dry food listing "30% protein" on the bag.

Convert guaranteed analysis pet food labels into true dry matter basis (DMB) and calculate hidden carbohydrates (NFE) to compare canned, raw, and dry kibble diets accurately.

Parameters

Pet Food Format

Select the general style of food to use standard baseline moisture and ash defaults.

Moisture (Max % on Label)%

07890

Guaranteed maximum moisture printed on the guaranteed analysis panel.

Crude Protein (Min % on Label)%

11080

Guaranteed minimum crude protein percentage printed on the label.

Crude Fat (Min % on Label)%

0.5560

Guaranteed minimum crude fat percentage printed on the label.

Crude Fiber (Max % on Label)%

0.1125

Guaranteed maximum crude fiber percentage printed on the label.

Crude Ash / Minerals (Est. %)%

0.5220

Mineral residue. If not listed on label, use 2.0% for wet food or 7.5% for dry kibble.

Calculated Output

True Carbohydrate Content (Dry Matter)

18.2%Carbohydrates (DMB)45.5% Protein (22% Solid Matter)

What This Result Means

This food contains 22% dry matter and 78% water. On a Dry Matter Basis (DMB), it provides 45.5% protein, 22.7% fat, and 18.2% carbohydrates (NFE). This macronutrient ratio provides a balanced protein-to-carbohydrate profile suitable for healthy adult dogs and active pets.

Calculation Details & Equivalents

Dry Matter Content (Solid Food)

22%

Carbohydrates / NFE (Dry Matter Basis)

18.2%

Crude Protein (Dry Matter Basis)

45.5%

Crude Fat (Dry Matter Basis)

22.7%

Crude Fiber (Dry Matter Basis)

4.5%

Mineral Ash (Dry Matter Basis)

9.1%

As-Fed Carbohydrates (Printed Can/Bag Basis)

Nutrient Evaluation

Moderate Healthy Carbohydrates (12%–28% DMB)

Veterinary & Animal Science Advisory

This calculator provides evidence-based estimates derived from published veterinary equations (NRC, WSAVA, FAO). Outputs are intended for educational and decision-support guidance only. Always consult a licensed veterinarian or qualified specialist for clinical diagnosis, treatment planning, or prescription drug administration.

Understanding the Pet Food Dry Matter & Carbohydrate Calculator

What This Calculator Does

Pet food labels can be surprisingly misleading because water dilutes guaranteed analysis numbers. A canned food with 10% protein sounds lower in nutrients than a bag of dry kibble with 28% protein, but canned food is mostly water. Converting nutrients to a Dry Matter Basis (DMB) strips out the moisture so you can see the real protein, fat, and carbohydrate levels.

How to Use This Calculator

Enter the guaranteed analysis percentages found on your pet food can or bag: moisture, crude protein, crude fat, crude fiber, and ash. If ash is not printed on your label, the calculator automatically provides accurate industry-standard defaults (2.0% for wet food, 7.5% for dry kibble). The tool immediately calculates true dry matter nutrients and hidden carbohydrate percentages.

Key Factors That Affect the Result

Moisture Content: Water has zero calories and zero nutrients. Removing moisture reveals true nutritional concentration.
Hidden Carbohydrates (NFE): Pet food regulations do not mandate carbohydrate disclosures. NFE math uncovers starch and sugar filler levels.
Ash (Mineral Content): Ash represents essential minerals (calcium, phosphorus, magnesium). Omitting ash skews carbohydrate estimates by 2% to 8%.
Species Biological Needs: Obligate carnivores like cats require high protein and minimal carbs (<10% DMB), whereas dogs efficiently utilize moderate starch.

Why This Matters for Your General & Conversions

Knowing exact Dry Matter and carbohydrate percentages is crucial for managing common pet conditions. Diabetic cats need ultra-low-carbohydrate wet diets to enter diabetic remission, overweight dogs require controlled-calorie lean protein, and pets with kidney issues need tightly regulated phosphorus and protein density.

Veterinary Advisory: This pet food dry matter calculator provides nutritional estimates based on AAFCO guaranteed analysis standards and the Nitrogen-Free Extract (NFE) method. Because package panels list legal minimums and maximums rather than median laboratory assays, values are close practical approximations. Always consult your veterinarian or a board-certified veterinary nutritionist before making radical changes to your pet’s diet, especially for animals diagnosed with diabetes, chronic kidney disease (CKD), or pancreatitis.

Reviewed & verified by Dr. Imad Khan, DVM, MSc · Doctor of Veterinary Medicine & Masters in Poultry Science · View editorial credentials →

Formula & Mathematical Methodology

Standard Mathematical Formula

Dry Matter % = 100% - Moisture %; DMB Nutrient % = (As-Fed Nutrient % ÷ Dry Matter %) × 100; As-Fed Carbohydrates (NFE) % = 100% - (Protein % + Fat % + Fiber % + Moisture % + Ash %); DMB Carbohydrates % = (NFE % ÷ Dry Matter %) × 100

Formula Variables Defined

DMDry Matter(%)

Percentage of food remaining once all moisture is removed

MoistureMoisture Content(%)

Guaranteed analysis maximum moisture percentage printed on label

ProteinCrude Protein(%)

Guaranteed analysis minimum crude protein percentage

FatCrude Fat(%)

Guaranteed analysis minimum crude fat percentage

FiberCrude Fiber(%)

Guaranteed analysis maximum crude fiber percentage

AshMineral Ash(%)

Total mineral content (calcium, phosphorus, magnesium, zinc)

NFENitrogen-Free Extract (Carbohydrates)(%)

Estimated soluble starches and sugars calculated by difference

Step-by-Step Calculation Example

Comparing Canned Wet Food with Dry Kibble

A canned cat food label states 10% crude protein, 5% crude fat, 1% crude fiber, 78% moisture, and 2% ash.

1. Calculate Dry Matter: 100% - 78% moisture = 22% solid matter.
2. Calculate DMB Protein: (10% ÷ 22%) × 100 = 45.45%.
3. Calculate DMB Fat: (5% ÷ 22%) × 100 = 22.73%.
4. Calculate DMB Fiber: (1% ÷ 22%) × 100 = 4.55%.
5. Calculate As-Fed Carbohydrates (NFE): 100% - (10 + 5 + 1 + 78 + 2) = 4.0%.
6. Calculate DMB Carbohydrates: (4.0% ÷ 22%) × 100 = 18.18%.

Final Output: Dry Matter is 22%. On a Dry Matter Basis (DMB), the food provides 45.5% protein, 22.7% fat, 4.5% fiber, and 18.2% carbohydrates (NFE).

Key Assumptions

Guaranteed analysis percentages on commercial packaging represent legal minimums (protein, fat) and maximums (moisture, fiber) mandated by AAFCO, rather than precise laboratory median values.
Commercial wet foods generally contain 1.5% to 2.5% ash, while dry extruded kibbles generally contain 6.5% to 8.5% ash when unlisted on the label.

Biological Limitations

Nitrogen-Free Extract (NFE) accounts for all non-structural carbohydrates (starches, oligosaccharides, and simple sugars) by mathematical subtraction, but does not distinguish low-glycemic dietary fibers from rapidly absorbable starches.
Prescription veterinary therapeutic diets with specialized low-protein or ultra-hydrolyzed profiles may require manufacturer specification sheets for micronutrient profiling.

Verified Scientific & Veterinary Sources

Version: 1.0.0•Methodology Reviewed: 2026-09-25

1. Official Publication: Pet Food Regulations & Nutrient Profilesguideline

Association of American Feed Control Officials (AAFCO) (2023). AAFCO Official Publication

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2. WSAVA Global Nutrition Guidelines & Calorie Calculator Referenceguideline

World Small Animal Veterinary Association (WSAVA) Global Nutrition Committee (2021). Journal of Small Animal Practice

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3. Nutrient Requirements of Dogs and Catstextbook

National Research Council (NRC) Committee on Animal Nutrition (2006). National Academies Press, Washington, D.C.

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