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How to compare two cat foods fairly
A bag price alone does not tell you which cat food costs less to feed. Pack sizes differ, calorie densities differ, and a wet food contains much more water than a dry food. This cat food comparison tool brings those differences into the same calculation. Enter two products and one daily calorie target to compare estimated daily portions, feeding costs, and selected nutrients on a dry matter basis.
The results answer specific arithmetic questions. They do not rank foods for nutritional quality, predict which product your cat will tolerate, or establish whether either food is suitable for a medical condition. Start with foods appropriate for your cat, then use the figures to understand the practical differences between them. A lower cost or higher protein percentage is not automatically the better choice.
Gather the information from both labels
For each food, enter a product name, package price, package weight in grams, and calories per 100 grams. Use the same currency for both prices. The name is simply a label to help identify each result, so include the flavour or variety when similar products have different recipes. Check the exact product rather than copying information from another size or an older listing.
If a label gives calories per kilogram, divide that number by ten to obtain calories per 100 grams. A food containing 3,800 kcal per kilogram therefore contains 380 kcal per 100 grams. If calories are listed per can, divide the can's calories by its weight in grams and multiply by 100. Keep the package weight and calorie information tied to the same product.
Enter the moisture, protein, fat, and fibre percentages from each label. These figures support the dry matter comparison. They are percentages, not grams per serving. The form rejects a combined percentage above 100 because those entries cannot describe a consistent composition. That check catches some mistakes but does not verify the manufacturer's analysis or turn label guarantees into laboratory measurements.
Use the same calorie target
The daily calorie target gives both foods a common basis for comparison. The tool calculates how many grams of each product would provide that entire target. If your cat's agreed target is 240 kcal, both food columns are evaluated at 240 kcal. This avoids comparing a small serving of one food with a large serving of the other.
Treats and other foods complicate a real feeding plan. If you want to compare only the main food allowance, enter the calories allocated to that allowance. For a mixed diet, this side-by-side result is a comparison of alternatives, not a prescription to feed both displayed daily amounts together. Use the cat feeding calculator to divide one allowance between wet and dry foods.
Understand the cost calculations
Daily grams equal the calorie target divided by calories per 100 grams, multiplied by 100. Cost per gram equals package price divided by package grams. Multiplying daily grams by cost per gram gives the daily feeding cost. Cost per 100 kcal provides another common unit that is independent of the chosen daily target.
Suppose Food A costs 24 for a 2,000 gram bag and provides 400 kcal per 100 grams. At a 240 kcal target, its daily portion is 60 grams. Each gram costs 0.012, so the estimated daily food cost is 0.72. Its cost per 100 kcal is 0.30. These values use the entered currency; the calculator does not perform exchange-rate conversion.
Suppose Food B costs 18 for 1,200 grams and provides 300 kcal per 100 grams. The same calorie target requires 80 grams, costing 1.20 per day. Its cost per 100 kcal is 0.50. Although Food B has the cheaper package, it costs more in this example to supply the same energy. Neither calculation accounts for waste, delivery charges, or a discount you did not include in the price.
What dry matter percentages mean
Dry matter is the portion left after water is excluded. The calculation subtracts the moisture percentage from 100, then divides each listed nutrient percentage by that remainder and multiplies by 100. This makes a wet and dry food easier to compare without water dominating the apparent difference. The FDA's pet food guidance explains why moisture matters when comparing label percentages.
For example, a wet food with 80% moisture and 10% protein has 20% dry matter. Its protein value on a dry matter basis is 10 divided by 20, multiplied by 100, or 50%. A dry food with 10% moisture and 35% protein gives approximately 38.9% protein on a dry matter basis. The original label numbers of 10 and 35 describe different amounts of water.
Guaranteed analyses often use minimum or maximum values. Combining those guarantees produces an estimate, not a precise recipe composition. A dry matter percentage also does not describe the percentage of calories supplied by that nutrient. This tool does not calculate digestibility, amino acid balance, carbohydrate content, or the suitability of a therapeutic diet.
Make the comparison useful in everyday shopping
Compare prices available to you today and decide whether to include delivery in both products consistently. For multipacks, add the edible contents of all cans or pouches rather than the shipping weight. If a product is temporarily discounted, record that separately so the comparison does not become misleading when the price returns to normal.
Consider whether you can use a larger package within the manufacturer's storage guidance. A theoretical saving can disappear if food is discarded. The food duration calculator estimates supply from daily grams, while the food cost calculator projects recurring spending. Recheck the comparison whenever a recipe, package size, price, or feeding allowance changes.
Frequently asked questions
Does the highlighted cost tell me which food to buy?
It identifies an arithmetic difference using your entries. Suitability also depends on life stage, nutritional adequacy, tolerance, availability, and veterinary advice when relevant. Use the cost result as one part of your decision rather than an overall product score.
Can I compare two wet foods or two dry foods?
Yes. The same method works for either pair. Dry matter values can still be useful when their moisture levels differ, and cost per calorie can reveal differences hidden by package pricing. Enter both products in the required units.
Why does a food with more calories need fewer grams?
Calorie density describes how much energy a given weight supplies. A more concentrated food reaches the same target with a smaller portion. Fewer grams do not necessarily mean lower feeding cost because the price per gram also matters.
Can these results replace a feeding recommendation?
No. The tool uses the calorie target you supply and assumes each food provides that amount on its own. It does not establish your cat's needs. Confirm the allowance separately, then measure portions and review the plan as your cat's circumstances change.