Reviewed by: Dr. Jennifer Walsh, Veterinary Nutritionist, DVM
Quick answer: A healthy 10-pound indoor neutered adult cat needs approximately 200–250 kcal per day. Use the calculator above or follow the formula in Section 2 to get the exact number for your cat.
Feeding too many calories leads to obesity — now affecting over 60% of pet cats according to the Association for Pet Obesity Prevention (APOP). Feeding too few stunts growth in kittens and causes muscle wasting in seniors. This guide gives you the vet-standard formula, ready-to-use charts, and a weight-loss calculator so you never have to guess.
Cat Calorie Calculator
Enter your cat's weight and life stage in the calculator above to get their personalized daily calorie target. To calculate manually, follow the step-by-step formula in Section 2 below.
The Vet-Standard Formula: RER and MER Explained
Veterinary nutritionists calculate a cat's daily calorie needs in two steps. Both the American Veterinary Medical Association (AVMA) and the World Small Animal Veterinary Association (WSAVA) endorse this approach.
Note on terminology: "Calories" on pet food labels and in this guide always means kilocalories (kcal). The two terms are used interchangeably in veterinary practice.
Step 1 — Calculate RER (Resting Energy Requirement)
RER is the calories your cat needs to sustain basic life functions at complete rest: breathing, circulation, organ activity, and cell repair. It is the foundation of all feline calorie calculations.
Formula: RER (kcal/day) = 70 × (body weight in kg)0.75
If your cat's weight is in pounds: kg = lbs ÷ 2.205
Worked Example — 10-pound cat
- Convert: 10 lbs ÷ 2.205 = 4.54 kg
- Raise to the 0.75 power: 4.540.75 = 3.19
- Multiply by 70: 70 × 3.19 = ~223 kcal/day RER
Step 2 — Calculate MER (Maintenance Energy Requirement)
MER is your cat's actual daily calorie target. It multiplies the RER by a life-stage factor that accounts for activity level, age, reproductive status, and weight goal.
Formula: MER (kcal/day) = RER × Life-Stage Multiplier
Worked Example — neutered indoor adult, 10 lbs
- RER = ~223 kcal/day
- Multiplier for neutered indoor adult = 1.2
- MER = 223 × 1.2 = ~268 kcal/day
This cat should eat approximately 268 kcal per day to maintain their healthy weight.
MER Multiplier Table — Calorie Factors by Life Stage and Status
| Cat Category | Multiplier | Notes |
|---|---|---|
| Kitten under 4 months | 2.5× RER | Rapid growth; very high energy demand |
| Kitten 4–12 months | 2.0× RER | Still growing; needs roughly double adult calories |
| Intact (unneutered) adult | 1.4× RER | Higher metabolic rate than neutered cats |
| Neutered indoor adult (average activity) | 1.2× RER | Most common pet cat profile |
| Inactive / sedentary adult | 1.0× RER | Minimal activity; prone to weight gain |
| Active / outdoor adult | 1.4× RER | Frequent roaming or play outdoors |
| Obese-prone adult | 1.0× RER | Weight maintenance for high-risk cats |
| Weight loss goal | 0.8× RER of ideal weight | Calculate RER at target weight, not current weight |
| Pregnant (early to mid) | 1.6–2.0× RER | Increased demand for fetal development |
| Nursing / lactating queen | 2.0–2.5× RER | Highest calorie demand of any life stage |
| Senior 7–11 years | 1.1–1.4× RER | Varies; may increase if muscle loss is occurring |
| Geriatric 12+ years | 1.4–1.6× RER | Older seniors often need more calories, not fewer |
| Recovering from illness or surgery | 1.5× RER | Extra energy needed for healing and immune response |
Important: These multipliers are starting points. Individual cats vary by up to 50% from predicted values due to metabolic differences. Weigh your cat every 2–4 weeks and adjust portions based on weight trend, not a single measurement.
Cat Calorie Chart by Weight — Quick Reference
Use this table to find your cat's daily calorie target without doing the math. Find your cat's weight in the left column, then read across to the column that matches their situation.
| Cat Weight | Neutered Indoor (1.2×) | Active or Intact (1.4×) | Sedentary (1.0×) | Weight Loss (0.8× of ideal) |
|---|---|---|---|---|
| 6 lbs (2.7 kg) | ~157 kcal | ~183 kcal | ~131 kcal | ~105 kcal |
| 7 lbs (3.2 kg) | ~172 kcal | ~201 kcal | ~143 kcal | ~115 kcal |
| 8 lbs (3.6 kg) | ~196 kcal | ~228 kcal | ~163 kcal | ~130 kcal |
| 9 lbs (4.1 kg) | ~217 kcal | ~253 kcal | ~181 kcal | ~145 kcal |
| 10 lbs (4.5 kg) | ~237 kcal | ~276 kcal | ~197 kcal | ~158 kcal |
| 11 lbs (5.0 kg) | ~257 kcal | ~300 kcal | ~214 kcal | ~171 kcal |
| 12 lbs (5.4 kg) | ~276 kcal | ~322 kcal | ~230 kcal | ~184 kcal |
| 13 lbs (5.9 kg) | ~295 kcal | ~344 kcal | ~246 kcal | ~197 kcal |
| 14 lbs (6.4 kg) | ~314 kcal | ~367 kcal | ~262 kcal | ~210 kcal |
| 15 lbs (6.8 kg) | ~332 kcal | ~388 kcal | ~277 kcal | ~222 kcal |
| 16 lbs (7.3 kg) | ~352 kcal | ~410 kcal | ~293 kcal | ~234 kcal |
| 18 lbs (8.2 kg) | ~388 kcal | ~452 kcal | ~323 kcal | ~258 kcal |
| 20 lbs (9.1 kg) | ~422 kcal | ~493 kcal | ~352 kcal | ~282 kcal |
Quick rule of thumb: A healthy 10-pound indoor neutered adult cat needs about 200–250 kcal/day. An active or outdoor cat of the same weight needs closer to 270–300 kcal/day. These are estimates — the formula above is more accurate for individual cats.
How Many Calories Does a Cat Need by Life Stage?
Kittens (0–12 Months)
Kittens grow from 3–4 ounces at birth to 8–10 pounds in 12 months. That growth demands enormous energy — kittens need roughly 2–2.5× more calories per kg of body weight than adult cats. A 3-pound kitten may need up to 200 kcal/day — nearly the same as an 8-pound adult — purely because of growth demands. Feed kitten-formulated food (calorie-dense and nutrient-rich) until at least 12 months old.
| Kitten Age | Approx. Weight | RER (kcal) | Multiplier | Daily Calories |
|---|---|---|---|---|
| 4–8 weeks | 0.5–1 lb (0.2–0.5 kg) | ~35–55 kcal | 2.5× | ~85–135 kcal |
| 2–3 months | 1.5–2 lbs (0.7–0.9 kg) | ~60–75 kcal | 2.5× | ~150–190 kcal |
| 3–4 months | 2.5–3.5 lbs (1.1–1.6 kg) | ~85–110 kcal | 2.5× | ~210–275 kcal |
| 4–6 months | 3.5–5 lbs (1.6–2.3 kg) | ~105–140 kcal | 2.0× | ~210–280 kcal |
| 6–9 months | 5–7 lbs (2.3–3.2 kg) | ~140–172 kcal | 2.0× | ~280–344 kcal |
| 9–12 months | 7–9 lbs (3.2–4.1 kg) | ~172–200 kcal | 2.0× | ~344–400 kcal |
Feed kittens 3–4 small meals per day up to 6 months, then 2–3 daily meals until age 1. Do not restrict kitten food intake unless directed by a vet — kittens self-regulate better than adult cats.
Young Adults (1–6 Years)
Once fully grown, calorie needs stabilize. Most house cats become less active after age 2 but continue to receive the same portions — this is when obesity risk begins. Switch to an adult formula and measure portions carefully.
Mature Adults (7–10 Years)
Metabolism typically slows. Many cats in this range need 10–20% fewer calories than their younger adult years unless they remain very active. Calorie-controlled or "weight management" formulas become appropriate for many cats at this stage.
Senior Cats (11–14 Years)
Contrary to popular belief, many senior cats need more calories, not fewer. Muscle loss (sarcopenia) is common after age 11, and maintaining calorie and protein intake helps preserve lean body mass. However, sedentary seniors may still gain weight, so close monitoring is essential.
| Age | Typical Condition | Calorie Approach | MER Multiplier |
|---|---|---|---|
| 7–10 years (Mature Adult) | Slowing metabolism; moderate activity | Slight reduction for overweight; maintain for healthy weight | 1.1–1.2× |
| 11–14 years (Senior) | Muscle loss; decreased digestive efficiency | Maintain or slightly increase; prioritize protein quality | 1.1–1.4× |
| 15+ years (Geriatric) | Weight loss common; reduced appetite | Increase calories; offer highly digestible food in small meals | 1.4–1.6× |
Geriatric Cats (15+ Years)
Cats 15 and older often struggle to maintain weight due to reduced digestive efficiency, dental pain, and chronic illness. Many benefit from high-calorie, highly digestible food offered in small, frequent meals. A vet-guided nutrition plan is critical at this stage.
Cat Weight Loss Calorie Calculator
If your cat is overweight, you do not calculate based on their current weight — you calculate based on their estimated ideal weight. Feeding at the overweight cat's RER would still be too many calories for safe weight loss.
How to Calculate Weight-Loss Calories
- Determine ideal weight — Ask your vet, or use the BCS scale in Section 7. For most domestic cats, ideal weight is 8–10 lbs (3.6–4.5 kg).
- Calculate RER at ideal weight — RER = 70 × (ideal weight in kg)0.75
- Apply the weight-loss multiplier — MER = RER × 0.8
- Divide into multiple small meals — 2–3 measured meals daily is better than one large meal.
Worked Example
A cat currently weighs 14 lbs (6.4 kg). Ideal weight is estimated at 10 lbs (4.5 kg).
- RER at 4.5 kg = 70 × (4.5)0.75 = 70 × 3.03 = ~212 kcal
- Weight-loss MER = 212 × 0.8 = ~170 kcal/day
This cat should be fed approximately 170 kcal per day to lose weight safely.
| Current Weight | Estimated Ideal Weight | Daily Calorie Target | Safe Weekly Loss |
|---|---|---|---|
| 11 lbs (5 kg) | 9 lbs (4.1 kg) | ~145 kcal | ~0.5–1 oz |
| 12 lbs (5.4 kg) | 10 lbs (4.5 kg) | ~158 kcal | ~0.5–1 oz |
| 14 lbs (6.4 kg) | 10 lbs (4.5 kg) | ~170 kcal | ~1–1.5 oz |
| 16 lbs (7.3 kg) | 11 lbs (5 kg) | ~171 kcal | ~1–1.5 oz |
| 18 lbs (8.2 kg) | 12 lbs (5.4 kg) | ~184 kcal | ~1.5–2 oz |
| 20 lbs (9.1 kg) | 13 lbs (5.9 kg) | ~197 kcal | ~1.5–2 oz |
Safe rate of weight loss: 0.5–1% of body weight per week. For a 14-pound cat, that is about 1–1.4 ounces (30–40 grams) per week.
Critical warning: Never drastically restrict a cat's food or allow them to stop eating. Cats that go without food for 24–48 hours are at serious risk of hepatic lipidosis (fatty liver disease) — a potentially fatal condition. Always reduce calories gradually and under veterinary supervision.
Cat Body Condition Score (BCS): Is Your Cat at a Healthy Weight?
The Body Condition Score (BCS) is the veterinary 1–9 scale used to assess whether a cat is underweight, at an ideal weight, or overweight. It is based on physical assessment, not just the number on the scale. Two cats can weigh the same but have very different body compositions.
| BCS Score | Category | Physical Description | Calorie Action |
|---|---|---|---|
| 1–2 / 9 | Severely underweight | Ribs, spine, and hip bones very prominent; no body fat; visible muscle wasting | Increase calories immediately under vet supervision |
| 3 / 9 | Underweight | Ribs easily felt; minimal fat; prominent waist and tummy tuck | Increase daily calorie intake by 20–30% |
| 4 / 9 | Slightly lean | Ribs easily felt with slight fat; defined waist and tummy tuck | Small calorie increase; monitor weekly |
| 5 / 9 | Ideal | Ribs felt with slight fat cover; visible waist; slight tummy tuck | Maintain current calorie level |
| 6 / 9 | Slightly overweight | Ribs felt with moderate fat; waist barely visible; slight abdominal rounding | Reduce calories by 10–15% |
| 7 / 9 | Overweight | Ribs hard to feel under heavy fat; no visible waist; rounded abdomen | Begin weight-loss plan: 0.8× RER of ideal weight |
| 8–9 / 9 | Obese | Ribs not palpable; heavy fat deposits; pendulous abdomen; fat on neck and limbs | Urgent vet-supervised weight-loss program |
How to Assess BCS at Home
- Rib check: Run fingers along the ribcage without pressing hard. You should feel individual ribs under a thin layer of fat — like knuckles under a thin cloth. If you cannot feel ribs at all, your cat is overweight.
- Waist check (from above): A healthy cat has a visible waist tapering behind the ribs. An overweight cat has a straight or rounded silhouette.
- Abdominal tuck (from the side): A healthy cat's belly tucks slightly upward behind the ribcage. An overweight cat has a saggy or rounded belly.
How Many Calories Are in Cat Food? Wet vs. Dry vs. Raw
| Food Type | Calorie Range | Average Calories | Notes |
|---|---|---|---|
| Dry kibble per cup | 300–500 kcal/cup | ~350–400 kcal/cup | High calorie density; easy to overfeed with cup measures |
| Dry kibble per 100g | 330–450 kcal/100g | ~380 kcal/100g | Always weigh; kibble size affects cup volume significantly |
| Wet food — 3 oz (85g) can | 60–100 kcal/can | ~75–80 kcal/can | Low calorie density; great for weight management and hydration |
| Wet food — 5.5 oz (156g) can | 130–200 kcal/can | ~150–175 kcal/can | Standard single-serving size |
| Raw food per 100g | 100–180 kcal/100g | ~130 kcal/100g | Varies widely by protein source and fat content |
| Freeze-dried raw per 100g | 400–550 kcal/100g | ~480 kcal/100g | Very calorie-dense; use sparingly as topper |
How to Calculate Food Portions from Calories
Formula: Daily Food Amount (g) = Daily Calorie Target ÷ (Food kcal per 100g) × 100
Example: A cat needs 250 kcal/day. Wet food contains 85 kcal per 100g.
250 ÷ 85 × 100 = ~294 grams per day of that food.
Wet Food vs. Dry Food for Calorie Control
Wet food is generally preferred for weight management. Its high water content (70–80% moisture) means fewer calories per gram, and cats feel more satiated after wet food. Dry kibble is convenient but calorie-dense — easy to overfeed, especially with cup measurements instead of weighing.
Many vets recommend a combination of wet and dry food: wet food for the majority of the calorie budget, with a small measured amount of dry kibble for enrichment or dental support.
Counting Treat Calories — The 10% Rule
Treats are one of the most overlooked sources of excess calories. A single commercial cat treat typically contains 2–5 kcal. The veterinary standard is that treats should account for no more than 10% of a cat's total daily calories. Any treat calories must be subtracted from the daily meal budget.
| Cat Weight | Daily Calorie Target | Max Treat Budget (10%) | Approx. Treat Count (2 kcal each) |
|---|---|---|---|
| 8 lbs | ~196 kcal | ~20 kcal | ~10 small treats |
| 10 lbs | ~237 kcal | ~24 kcal | ~12 small treats |
| 12 lbs | ~276 kcal | ~28 kcal | ~14 small treats |
| 14 lbs | ~314 kcal | ~31 kcal | ~15–16 small treats |
Frequently Asked Questions
How many calories should a cat eat per day?
A healthy 10-pound indoor neutered adult cat needs approximately 200–250 kcal/day. The exact number depends on weight, activity level, age, and neutered status. Use the RER × MER formula for a personalized result.
How many calories does a 10-pound cat need?
A 10-pound (4.5 kg) neutered indoor adult needs approximately 237 kcal/day to maintain weight. An active or intact 10-pound cat may need closer to 276 kcal. A 10-pound cat on a weight-loss plan should eat approximately 158 kcal/day.
How many calories does a kitten need per day?
A 3-month-old kitten weighing 2.5–3 lbs may need 210–275 kcal/day. A 6-month-old kitten at 5–6 lbs may need 250–310 kcal/day. Always feed kitten-specific food formulated for these higher energy needs.
How many calories does a cat need to lose weight?
Feed at 80% of the RER calculated for the cat's ideal body weight. For most overweight cats this means 150–200 kcal/day in multiple small meals. Never restrict food so severely that the cat stops eating — fatal hepatic lipidosis risk is real. Always reduce calories gradually and consult your vet.
Do neutered cats need fewer calories?
Yes. Neutering reduces a cat's metabolic rate by roughly 20–30%. Neutered indoor cats use a MER multiplier of 1.2 versus 1.4 for intact cats. Reduce food portions after spaying or neutering to prevent post-operative weight gain.
How many calories are in dry cat food per cup?
A typical cup of dry kibble contains 300–500 kcal, averaging around 350–400 kcal/cup. This varies significantly by brand and formula. Always check the specific kcal/cup figure on the packaging, and weigh food in grams for accuracy — cup volume varies with kibble size.
How many calories are in a can of wet cat food?
A standard 3 oz (85g) can contains approximately 60–100 kcal (avg ~75–85 kcal). A larger 5.5 oz (156g) can typically contains 130–200 kcal. Premium and grain-free wet foods often run slightly higher — always check the label.
Can I free-feed my cat (leave food out all day)?
Free-feeding is generally not recommended for adult cats prone to weight gain — which includes most indoor neutered cats. Measured meals twice daily (or multiple small measured servings) give you better control over intake and let you notice appetite changes early, which can signal illness.
What is the difference between RER and MER in cats?
RER (Resting Energy Requirement) is the calories a cat needs to stay alive at rest — covering breathing, circulation, and organ activity. MER (Maintenance Energy Requirement) is RER multiplied by a life-stage factor that accounts for activity, age, and reproductive status. MER is the actual daily calorie target you feed to.
My cat seems always hungry — am I underfeeding them?
Not necessarily. Many cats beg persistently even when fully fed, especially after transitioning from free-feeding to measured meals. However, persistent intense hunger can also indicate hyperthyroidism, diabetes, intestinal parasites, or malabsorption. If your cat is at a healthy weight on an appropriate amount but still seems hungry, consult your vet to rule out underlying conditions.
How do I calculate calories for a pregnant cat?
A pregnant cat's needs increase steadily. For the first half of pregnancy, a slight increase above normal is sufficient. By late pregnancy and during nursing, calorie needs reach 2.0–2.5× RER — the highest demand of any feline life stage. Many vets recommend switching pregnant and nursing queens to kitten food, which is calorie-dense and nutrient-rich.
Summary
Obesity is the leading nutritional disease in domestic cats and is largely preventable through accurate portioning and regular monitoring. Underfeeding is equally serious in kittens, seniors, and nursing queens.
Use the formula (RER = 70 × weight in kg0.75, then MER = RER × life-stage multiplier), the calorie charts, and the BCS guide in this article to build a precise feeding plan. Weigh your cat every 2–4 weeks, read food labels carefully, count treat calories, and adjust portions based on ongoing weight trend. When in doubt, your veterinarian or a board-certified veterinary nutritionist is the best resource for your cat's individual profile.