To compare protein percentages in wet and dry cat food, first account for the water. A pouch listing 10% protein is not necessarily lower in protein on a dry-matter basis than kibble listing 36%. The calculation puts both figures on the same basis; it does not identify the best food for your cat.
What does dry matter mean?
Dry matter is what remains after the moisture is excluded. Use the protein and moisture percentages for the exact recipe. The calculation is: protein percentage ÷ (100 − moisture percentage) × 100. UK Pet Food explains this approach in its protein factsheet.
A worked comparison
The following numbers are fictional examples for practising the calculation, not actual foods or feeding recommendations.
| Figure | Wet food A | Dry food B |
|---|---|---|
| Protein as supplied | 10% | 36% |
| Moisture | 80% | 10% |
| Dry matter | 100 − 80 = 20% | 100 − 10 = 90% |
| Protein on a dry-matter basis | 10 ÷ 20 × 100 = 50% | 36 ÷ 90 × 100 = 40% |
The wet food has the higher dry-matter protein percentage in this example. This does not mean it supplies more protein per pouch or per day, or that every wet food has more protein than every dry food.
Why the higher number is not a quality score
A protein percentage does not establish the food's complete nutrient balance, digestibility or suitability for an individual cat. PDSA recommends an appropriate complete cat food, with veterinary advice for medical needs. Do not choose a therapeutic diet or change one because a spreadsheet ranks its protein differently.
A Maine Coon's size does not turn this comparison into a breed-specific protein target. This is label-reading arithmetic, not a method for prescribing a ration.
What should you do if moisture is missing?
Ask the manufacturer for the moisture and protein values for the exact recipe, and whether the figures supplied are typical analyses or guaranteed limits. Do not insert a guessed moisture value simply to finish the comparison. Keep a note of the product name, life-stage statement, date and the basis used for each figure. Mark an incomplete comparison as incomplete.
Keep food comparison separate from serving
Once you have selected suitable food, use its feeding instructions and individual veterinary guidance. Our mixed wet-and-dry portion guide covers a different calculation: combining the calories of both foods within one daily allowance. For the meaning of the label itself, see complete versus complementary food.
If using the Kitty Buffet, measure food before adding it to the removable bowls. The stand is serving equipment and does not change the nutritional properties of either food.
Sources checked 13 September 2026. Worked figures are illustrative only.
