Many cats eat both wet and dry food, but working out the right grams of each is harder than it looks. Wet food is mostly water, so 100 grams of wet food holds far fewer calories than 100 grams of dry food. Guessing equal weights gives far too many calories from the dry side, or far too few from the wet side. This mixer splits a daily calorie target into exact grams of each, using the energy values from the packets and the percentage mix you choose.
The maths is straightforward once the energy values are known. Take the daily calories and split them by the chosen percentage. If the target is 250 calories and the mix is half wet, then 125 calories come from wet food and 125 from dry. Wet food at 80 calories per 100 grams gives 156 grams. Dry food at 350 calories per 100 grams gives 36 grams. The total weight is 192 grams, but the calories are exactly 250. That is why grams alone, without calories, mislead.
A half and half calorie mix is a good default for most cats. It gives the hydration and palatability benefits of wet food, plus the convenience and dental crunch of dry food. Cats that drink little, have urinary problems, or are prone to constipation often do better with more wet food, for example 70 percent of calories from wet. Cats that graze, travel often, or need a food that keeps all day may do better with more dry. There is no single right mix, only the mix your cat eats happily and holds weight on.
Here is a worked example with different numbers. A cat needs 200 calories, the owner wants 70 percent wet, wet food is 90 calories per 100 grams, and dry food is 380 per 100 grams. Wet calories are 140, which is 156 grams of wet food. Dry calories are 60, which is 16 grams of dry food. That small pile of dry food surprises people, but it is correct: dry food is roughly four times as energy dense as wet food. Weigh both parts, because eyeballing the dry part is where the error creeps in.
Packet labels give the numbers you need, but check the units. Some wet pouches list calories per pouch, not per 100 grams. A 85 gram pouch at 80 calories per 100 grams holds 68 calories, not 80. Divide the pouch calories by the pouch weight and multiply by 100 to get the per 100 gram figure. For dry food, the label almost always gives calories per 100 grams directly, plus a feeding guide in grams that you can cross-check against this mixer.
Meal structure helps the mix work. Serve wet food as a set meal, morning or evening, and leave the measured dry portion for grazing or for a second meal. Do not leave wet food down all day: it dries out, loses smell, and grows bacteria, especially in warm rooms. Refrigerate opened wet food and use it within two to three days, warming it slightly before serving, since cold food smells less and many cats refuse it.
Cost is another reason to mix deliberately. Wet food costs much more per calorie, so a 100 percent wet diet can cost three or four times a dry diet. A 50 percent wet mix gives most of the hydration benefit at roughly half the extra cost. Work out the monthly cost of each part with a cost calculator, using the grams from this mixer, and the budget picture becomes clear. Do not let cost push the mix to 100 percent dry if the cat drinks very little, though: hydration problems cost more at the vet.
Changing the mix should be gradual, like any food change. Move the percentage by 10 to 20 points every few days, and watch the stool and the appetite. A cat that suddenly gets much more wet food may have softer stool for a day or two, which usually settles. A cat that suddenly gets much more dry food may drink more, which is expected. If vomiting, diarrhoea, or refusal lasts more than two days, slow the change and ask a vet if it continues.
Kittens and cats with medical conditions need a different approach. Kittens need kitten food, wet or dry, because adult food lacks the energy and nutrients for growth. Cats with kidney disease often need more wet food and a prescription diet, while cats with dental disease may struggle with dry kibble. This mixer is for healthy adult cats on complete foods. Any cat with a diagnosis should have its mix set by the vet, not by a general tool.
To sum up, mixing wet and dry food is a calorie split, not a weight split. Pick a percentage, read both packets, let this mixer give the grams, and weigh both parts every day. The cat gets variety, water, and crunch, and you get a number that actually adds up.