Cat Calorie Calculator By Weight or By Breed · How Many Calories a Cat Needs
Work out exactly how many calories your cat needs per day using the veterinary RER formula and AAHA feline life-stage factors. Choose weight or breed, life stage, lifestyle and body condition. It covers kittens, seniors, pregnancy, nursing and safe weight loss.
By Manzoor Ahmad · Updated October 18, 2026
Enter your cat’s current weight. Results update as you type.
Food details (for grams and cans)
Daily calories needed
—kcal/day
Enter your cat’s details.
Your cat’s energy multiplier (AAHA feline factor)
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What to do with this number
How many calories does a cat need per day?
A spayed or neutered indoor adult cat needs about 1.2–1.4 × its Resting Energy Requirement (RER), where RER = 70 × (body weight in kg)0.75. In practice that’s about 180 kcal for a 6 lb cat, 220 kcal for an 8 lb cat, 260 kcal for a 10 lb cat and 300 kcal for a 12 lb cat per day. Kittens need about 2.5 × RER, inactive cats about 1.0 × RER, and cats losing weight about 0.8 × RER of their ideal weight (AAHA 2021).
Key facts at a glance
- RER (Resting Energy Requirement) = 70 × kg0.75, the calories a cat burns at rest.
- AAHA feline factors: neutered adult 1.2–1.4, intact 1.4–1.6, inactive/obesity-prone 1.0, weight loss 0.8, pregnancy 1.6–2.0, nursing 2.0–6.0, kittens 2.5.
- Most indoor neutered cats need only about 200–300 kcal per day.
- Weight loss is planned from the ideal weight, and must be slow. Cats that stop eating risk hepatic lipidosis (fatty liver).
- Keep treats to 10% or less of daily calories.
Cat calorie calculator by weight: daily calorie chart
Daily calories for common cat weights using AAHA feline factors. Use the calculator above for your cat’s exact figure.
| Cat weight | RER | Weight loss* (0.8) | Inactive (1.0) | Neutered adult (1.2) | Intact adult (1.4) | Kitten (2.5) |
|---|---|---|---|---|---|---|
| 4 lb (1.8 kg) | 109 | 88 | 109 | 131 | 153 | 274 |
| 5 lb (2.3 kg) | 129 | 103 | 129 | 155 | 181 | 323 |
| 6 lb (2.7 kg) | 148 | 119 | 148 | 178 | 208 | 371 |
| 7 lb (3.2 kg) | 167 | 133 | 167 | 200 | 233 | 416 |
| 8 lb (3.6 kg) | 184 | 147 | 184 | 221 | 258 | 460 |
| 9 lb (4.1 kg) | 201 | 161 | 201 | 241 | 281 | 503 |
| 10 lb (4.5 kg) | 218 | 174 | 218 | 261 | 305 | 544 |
| 11 lb (5.0 kg) | 234 | 187 | 234 | 280 | 327 | 584 |
| 12 lb (5.4 kg) | 249 | 200 | 249 | 299 | 349 | 624 |
| 13 lb (5.9 kg) | 265 | 212 | 265 | 318 | 371 | 662 |
| 14 lb (6.4 kg) | 280 | 224 | 280 | 336 | 392 | 700 |
| 15 lb (6.8 kg) | 295 | 236 | 295 | 354 | 413 | 737 |
| 16 lb (7.3 kg) | 310 | 248 | 310 | 371 | 433 | 774 |
| 18 lb (8.2 kg) | 338 | 270 | 338 | 406 | 473 | 845 |
| 20 lb (9.1 kg) | 366 | 293 | 366 | 439 | 512 | 915 |
| 22 lb (10.0 kg) | 393 | 314 | 393 | 472 | 550 | 983 |
*Weight-loss calories apply to the cat’s ideal weight, not its current weight. A 14 lb cat with an ideal weight of 11 lb should use the 11 lb row.
Cat calorie calculator by breed: daily calories for 28 breeds
Breed mostly affects calories through adult size. A Maine Coon simply weighs more than a Devon Rex. Ranges run from the light end of each breed’s typical weight at 1.2 × RER to the heavy end at 1.4 × RER for neutered adults. Pick your breed in the By breed tab to personalize it.
| Breed | Typical adult weight | Neutered adult kcal/day | Energy tendency |
|---|---|---|---|
| Domestic Shorthair | 8–12 lb (3.6–5.4 kg) | 220–350 kcal | Moderate |
| Domestic Longhair | 8–12 lb (3.6–5.4 kg) | 220–350 kcal | Moderate |
| Maine Coon | 10–25 lb (4.5–11.3 kg) | 260–610 kcal | Moderate |
| Ragdoll | 10–20 lb (4.5–9.1 kg) | 260–510 kcal | Laid-back |
| Siamese | 6–12 lb (2.7–5.4 kg) | 180–350 kcal | Active |
| Persian | 7–12 lb (3.2–5.4 kg) | 200–350 kcal | Laid-back |
| Bengal | 8–15 lb (3.6–6.8 kg) | 220–410 kcal | Active |
| British Shorthair | 9–17 lb (4.1–7.7 kg) | 240–450 kcal | Laid-back |
| Sphynx | 6–12 lb (2.7–5.4 kg) | 180–350 kcal | Moderate |
| Scottish Fold | 6–13 lb (2.7–5.9 kg) | 180–370 kcal | Moderate |
| Abyssinian | 6–10 lb (2.7–4.5 kg) | 180–300 kcal | Active |
| Russian Blue | 7–12 lb (3.2–5.4 kg) | 200–350 kcal | Moderate |
| Norwegian Forest Cat | 9–20 lb (4.1–9.1 kg) | 240–510 kcal | Moderate |
| Siberian | 8–17 lb (3.6–7.7 kg) | 220–450 kcal | Moderate |
| Birman | 7–12 lb (3.2–5.4 kg) | 200–350 kcal | Moderate |
| Devon Rex | 5–9 lb (2.3–4.1 kg) | 160–280 kcal | Active |
| Cornish Rex | 6–10 lb (2.7–4.5 kg) | 180–300 kcal | Active |
| American Shorthair | 7–15 lb (3.2–6.8 kg) | 200–410 kcal | Moderate |
| Exotic Shorthair | 8–15 lb (3.6–6.8 kg) | 220–410 kcal | Laid-back |
| Savannah | 12–25 lb (5.4–11.3 kg) | 300–610 kcal | Active |
| Burmese | 6–12 lb (2.7–5.4 kg) | 180–350 kcal | Moderate |
| Oriental Shorthair | 6–12 lb (2.7–5.4 kg) | 180–350 kcal | Active |
| Tonkinese | 6–12 lb (2.7–5.4 kg) | 180–350 kcal | Moderate |
| Himalayan | 7–12 lb (3.2–5.4 kg) | 200–350 kcal | Laid-back |
| Ragamuffin | 10–20 lb (4.5–9.1 kg) | 260–510 kcal | Laid-back |
| Turkish Angora | 5–9 lb (2.3–4.1 kg) | 160–280 kcal | Moderate |
| Chartreux | 7–16 lb (3.2–7.3 kg) | 200–430 kcal | Moderate |
| Egyptian Mau | 6–11 lb (2.7–5.0 kg) | 180–330 kcal | Active |
Weights are approximate breed-standard ranges, and males are usually heavier than females. Use your own cat’s weight and body condition for an accurate result.
How to use this cat calorie calculator
- Choose “By weight” or “By breed”. Breed mode pre-fills a typical adult weight and lifestyle. You can edit both.
- Set life stage and lifestyle. Kittens, pregnant and nursing queens use their own AAHA factors. Adults and seniors adjust for activity and spay/neuter status.
- Pick the body condition score. At 6 or above, the calculator switches to a gentle weight-loss target based on an estimated ideal weight.
- Turn calories into food. See grams of dry food and cans of wet food here, or get full portions, mixed feeding and costs in the cat food calculator.
The cat calorie formula: RER × life-stage factor
Veterinarians estimate a cat’s energy needs in two steps. First they calculate the Resting Energy Requirement (RER), the calories needed at rest. Then they multiply it by a life-stage factor from the AAHA guidelines to get the Maintenance Energy Requirement (MER).
RER (kcal/day) = 70 × (body weight in kg)^0.75
MER (kcal/day) = RER × feline life-stage factor
Ideal weight (overweight cats) ≈ current weight ÷ (1 + 0.1 × (BCS − 5))
Because energy scales with metabolic body size (kg0.75), a 15 lb cat doesn’t need 50% more food than a 10 lb cat, only about 35% more. That’s why simple “calories per pound” rules often overfeed large cats.
Calorie factors for cats by life stage (AAHA 2021)
| Cat | MER factor | Notes |
|---|---|---|
| Neutered adult | 1.2–1.4 × RER | Most pet cats. Indoor cats sit at the lower end. |
| Intact adult | 1.4–1.6 × RER | Not spayed or neutered |
| Inactive / obesity-prone | 1.0 × RER | Low-activity indoor cats |
| Weight loss | 0.8 × RER (ideal weight) | Slow, vet-guided only |
| Kitten (growth) | 2.5 × RER | Based on current weight, recalculate often |
| Pregnant (gestation) | 1.6–2.0 × RER | Rises gradually through pregnancy |
| Nursing (lactation) | 2.0–6.0 × RER | Depends on litter size. Often free-fed. |
For a pregnant queen, the cat pregnancy calculator shows how far along she is. For an older cat, the cat age calculator confirms whether she’s a mature adult or a senior, which affects calorie needs.
How many calories should a cat eat to lose weight?
AAHA suggests 0.8 × RER of the ideal body weight for feline weight loss. Each body-condition point above 5 (on a 9-point scale) is often estimated as about 10% excess weight. A 14 lb cat at BCS 7 has an ideal weight of roughly 11.7 lb (5.3 kg), giving a weight-loss target of about 0.8 × 244 ≈ 195 kcal/day.
Never crash diet
Overweight cats that stop eating or lose weight too fast can develop hepatic lipidosis, a life-threatening liver condition. Slow and steady is essential.
Use a weight-loss food
Cutting a regular food sharply can under-supply protein and nutrients. Therapeutic diets keep cats satisfied on fewer calories.
Make cats work for food
Puzzle feeders, several small meals and play sessions help weight loss and reduce begging.
Worked example: a 10 lb neutered indoor cat
- Weight: 10 lb ÷ 2.2046 = 4.54 kg.
- RER: 70 × 4.540.75 ≈ 218 kcal/day.
- MER: 218 × 1.2 (neutered adult) ≈ 261 kcal/day, range about 260–300 kcal.
- Food: after 10% for treats, about 235 kcal ≈ 62 g of dry food (3,800 kcal/kg) or 2.8 three-ounce cans (85 kcal).
These are the calculator’s default values.
A pharmacist’s notes on cat calories and supplements
- Treats and pill pockets count. A few treats can be 10–20% of a small cat’s daily calories.
- Medications change appetite. Steroids increase hunger, while some antibiotics and thyroid medicines can reduce it. Recheck calories with your vet during long-term treatment.
- Hyperthyroidism, diabetes and kidney disease are common in older cats and change calorie needs. Weight loss despite a good appetite needs a vet visit.
- Never give acetaminophen or dog flea products containing permethrin. Both can be fatal to cats.
- Avoid onion and garlic in toppers, as the onion and garlic toxicity calculator explains. Cats are the most sensitive species.
More cat care tools
Calories are the starting point. These tools take you further:
Cat calorie calculator FAQs
Multiply the resting energy requirement (70 × body weight in kg to the power 0.75) by a life-stage factor. Most indoor neutered adults need 1.2–1.4 × RER, which is about 260 kcal for a 10 lb cat.
Convert pounds to kilograms (divide by 2.2), raise the result to the power 0.75, multiply by 70 to get RER, then multiply by your cat’s AAHA factor: 1.2 for a typical neutered adult. The calculator above does this instantly.
Mainly through size. Large breeds like Maine Coons and Norwegian Forest Cats weigh more, so they need more calories in total. Some breeds, such as Bengals and Abyssinians, tend to be more active, while Persians and British Shorthairs tend to be more sedentary.
About 2.5 × RER based on current weight, according to AAHA. A 4 lb kitten needs roughly 275 kcal a day. Recalculate every couple of weeks as it grows.
About 0.8 × RER of the ideal weight. For a cat whose ideal weight is 11 lb, that’s roughly 190 kcal a day. Lose weight slowly with your vet, because rapid weight loss can cause fatty liver disease.
Yes. AAHA lists 1.2–1.4 × RER for neutered adults versus 1.4–1.6 for intact cats. Many cats gain weight after neutering if portions aren’t reduced.
Typical indoor neutered cats need about 1.2 × RER, and very inactive cats about 1.0 × RER. For most cats that’s 200–300 kcal per day.
Pregnant cats need about 1.6–2.0 × RER, and nursing queens 2–6 × RER depending on litter size. Many vets recommend free-feeding kitten food during lactation.
Mature cats aged around 7–10 often need fewer calories. Many cats over about 11, however, lose muscle and digest food less efficiently, so they may need more. Weigh seniors monthly.
Divide daily food calories by the calories per cup, per kg or per can on the label. For full portions, including mixed feeding, use the cat food calculator.
No more than about 10% of daily calories. For a 10 lb cat that’s roughly 25 kcal, often just a few treats.
It’s a well-established starting estimate, but individual cats can vary by 20% or more. Weigh your cat every 2–4 weeks and adjust portions by about 10% if weight drifts.
Manzoor Ahmad
Pharmacist & health writer · 13+ years of web development and SEO experience
Manzoor is a pharmacist with more than nine years of experience writing evidence-based health, nutrition and supplement content. The RER formula and feline life-stage factors in this calculator follow the 2021 AAHA Nutrition and Weight Management Guidelines, and the life stages follow the 2021 AAHA/AAFP Feline Life Stage Guidelines. It gives a starting estimate. It does not replace your veterinarian.
Sources
Disclaimer: This cat calorie calculator gives educational estimates based on published veterinary formulas. Individual needs vary with metabolism, health, activity and food. Monitor your cat’s weight and body condition and consult your veterinarian, especially for kittens, pregnant or nursing cats, seniors, cats with medical conditions and any weight-loss plan.