Guaranteed analysis

The four values every label must carry

• Crude protein, minimum %. Total nitrogen × 6.25; tells you the floor, not the digestibility.
• Crude fat, minimum %. Floor for total dietary fat.
• Crude fiber, maximum %. Insoluble fiber ceiling.
• Moisture, maximum %. Caps water content; critical when converting to dry-matter basis.

Cat foods must additionally guarantee taurine. Many manufacturers voluntarily add EPA/DHA, omega-6, calcium, phosphorus, and others.

Converting to dry-matter basis (the only fair comparison)

Comparing a dry food (10% moisture) to a wet food (78% moisture) on the bag is meaningless, the wet food's numbers look small because most of the can is water. To compare, convert each to dry-matter basis (DMB):

1. Compute dry matter: 100 − moisture %. Wet food: 100 − 78 = 22%.
2. Divide each nutrient by dry matter and multiply by 100. Wet food crude protein 10% → 10 / 22 × 100 ≈ 45% DMB.
3. Now compare against the dry food's DMB number using the same formula.

What it does not tell you

Guaranteed analysis says nothing about ingredient digestibility, amino acid profile, vitamin sufficiency, or whether the food meets a complete-and-balanced standard. Two foods can carry identical guarantees and differ substantially in how the animal actually uses the nutrients. The AAFCO statement, the manufacturer's nutritional adequacy testing, and digestibility data fill those gaps.

Why it matters

Most owners read the front of the bag and skip the side panel. The guaranteed analysis is the only nutrient claim the manufacturer is legally accountable for, every other claim, including the hero ingredients on the front, is marketing.