How Much Should a Cat Eat Per Day?
Learn the exact daily food amount for your cat based on weight and life stage. Guide based on veterinary formulas.
How to Determine Your Cat's Daily Food Amount?
How much should you feed your cat? It's one of those questions that trips up a lot of new cat owners. The bag guidelines are a starting point, but your cat's actual needs depend on a few key factors — weight, life stage, and activity level all play a role.
What is RER (Resting Energy Requirement)?
RER is the calories your cat burns just by existing — breathing, keeping warm, basic organ function. It varies by weight, and the formula is: RER = 70 × (weight in kg ^ 0.75). A 4kg cat, for example, has an RER of around 200 kcal.
Calculating DER (Daily Energy Requirement)
Multiply RER by a life stage factor to get DER. Kittens need RER × 2.0–2.5, neutered adults × 1.2, seniors × 0.7–1.0. Then adjust by activity — add 20% for active cats, subtract 20% for couch potatoes.
Food Amount by Life Stage
- Kittens (0-1 year): Need the most calories of any life stage — growing takes a lot of energy. Feed 3 times a day.
- Adult cats (1-10 years): The goal shifts to weight maintenance. Twice a day works well for most adults.
- Senior cats (10+ years): Digestive efficiency drops with age, so food quality matters more. Stick with two meals a day.
What to Check When Choosing Cat Food
Check the "kcal per 100g" on the packaging — this is the number you actually need. Most dry foods land at 350–450 kcal/100g; wet foods are much lower at 70–120 kcal/100g. Fat content drives calories more than protein, so always use the actual number on the bag.
Feeding Amount Calculation Process
Weight (kg)
↓
RER = 70 × (weight ^ 0.75) kcal
↓
Apply life stage multiplier
(Kitten: ×2.0–2.5, Adult: ×1.2, Senior: ×0.7–1.0)
↓
Activity adjustment (±20%)
↓
DER (Daily Energy Requirement) kcal
↓
Divide by dry food calories (kcal/100g)
↓
Daily recommended food amount (g)Life Stage Calorie & Feeding Examples (4kg cat)
| Life Stage | Multiplier | Calories | Food Amount |
|---|---|---|---|
| Kitten | RER×2.0–2.5 | ~400–500 kcal | ~115–140g |
| Adult (Neutered) | RER×1.2 | ~240 kcal | ~65g |
| Senior/Weight Care | RER×0.7–1.0 | ~140–200 kcal | ~40–55g |
(Based on dry food at 350 kcal/100g)
Want the exact number for your cat? Try the free cat weight calculator — plug in weight, life stage, activity level, and food calories to get a personalized result.
Sources & References
- Cornell Feline Health Center - Feline Nutrition and Dietary Requirements
- AAFCO (Association of American Feed Control Officials) - Feline Nutrition Standards
- American Veterinary Medical Association - Feline Health Management
- ASPCA - Cat Nutrition and Obesity Prevention
Veterinary Consultation is Important
This is a general guide — every cat is different. If your cat has obesity, diabetes, or kidney disease, check with your vet before making changes to their diet.