How Much to Feed a Cat: Daily Calories, Cups, and Cans, Including Weight Loss
October 29, 2026
Like dogs, cats are fed by calories. The resting energy requirement (RER) is 70 × (weight in kg)^0.75. A neutered adult indoor cat needs roughly 1.2 times RER; an intact adult, 1.4; an active or growing cat, more; and an overweight cat on a diet, less.
A 4.5 kg (about 10 pound) neutered cat has RER = 70 × 4.5^0.75 = 70 × 3.09 = 216 kcal. At 1.2 × RER, the daily need is about 260 kcal.
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Dry food typically has 350 to 400 kcal per cup. At 370 kcal per cup, 260 kcal is 0.70 cup, a bit over two-thirds of a cup, divided across two or more meals. A standard 3-ounce can of wet food has about 70 to 100 kcal; at 80 kcal, 260 kcal is 3.25 cans. Mixed feeding: for example, one can (80 kcal) plus half a cup of dry food (185 kcal) totals 265 kcal. Always check the calorie content on your food's label, which varies widely between brands. Measure dry food with a kitchen scale, since a cup scoop can vary by 20% or more: that is a difference of about 50 kcal a day, enough for a pound of weight gain in a few months.
| Cat weight | RER (kcal) | Neutered adult (1.2 x RER) | Dry food at 370 kcal/cup | Wet food at 80 kcal/can |
|---|---|---|---|---|
| 3.5 kg (7.7 lb) | 179 | 215 | 0.58 cup | 2.7 cans |
| 4.5 kg (9.9 lb) | 216 | 260 | 0.70 cup | 3.2 cans |
| 5.5 kg (12.1 lb) | 251 | 302 | 0.82 cup | 3.8 cans |
Weight Loss Plan
If the cat weighs 5.5 kg but its ideal weight is 4.5 kg, base feeding on the ideal weight: a common starting point is RER of the target weight, 216 kcal a day, about 0.58 cup of the dry food above, less than the 302 kcal for maintaining 5.5 kg. Aim for a loss of 0.5% to 1% of body weight a week (about 30 to 55 g). Cats must not lose weight too fast, as rapid fasting can cause a dangerous liver condition (hepatic lipidosis). Weigh regularly and ask your veterinarian to supervise the plan.
Practical Feeding Tips
Include wet food to increase water intake and satiety. Use puzzle feeders to slow down eating and add activity. Treats should be under 10% of daily calories. Kittens need two to three times the calories per kilogram of an adult, and senior cats may need fewer calories but more protein. Fresh water should always be available.
Body Condition
Use a body condition score chart: you should feel the ribs with light pressure and see a waist from above. Adjust the amount by 10% when the weight trend isn't what you want. This article is general information; consult a veterinarian for your cat.
Frequently Asked Questions
How do I calculate a cat's calories?
RER = 70 × (kg)^0.75, then multiply by about 1.2 for a neutered adult.
How much dry food does a 10-pound cat need?
About 0.7 cup of a 370 kcal per cup food.
How fast should an overweight cat lose weight?
About 0.5% to 1% of body weight per week.
Why measure food by weight?
Cup scoops vary and can cause overfeeding.
What is a danger of crash diets in cats?
Hepatic lipidosis, a serious liver condition.