# Cat Food Portion Calculator Calculate your cat's daily food portion in cups and grams from body weight, life stage, and your food's calorie density. --- - **Canonical URL:** https://dothecalculation.com/calculators/cat-food-portion-calculator - **Category:** Hobbies & Leisure Utilities - **Publisher:** Do The Calculation (https://dothecalculation.com) - **Cost:** Free, no account or sign-up required - **Privacy:** Runs entirely in the browser; inputs are never sent to a server - **Methodology:** https://dothecalculation.com/methodology --- ## Cat Food Portion Calculator Find a starting daily food portion for your cat in cups and grams, using the same Resting Energy Requirement formula veterinary nutrition guidance is built on. - Daily portion in both cups and grams - Life-stage factors for neutered, intact, weight-management and kitten cats - Per-feeding split for multiple daily meals ## Quick Answer — How Much Should I Feed My Cat? **The core formula:** Resting Energy Requirement (RER, kcal/day) = 70 × (body weight in kg)^0.75. Maintenance Energy Requirement (MER) = RER × a life-stage factor. Daily portion = MER ÷ your food's calories per cup. **Quick reference (350 kcal/cup dry food):** • 10 lb neutered adult cat (factor 1.2) → **0.75 cups/day** (85.8 g/day) • 14 lb cat on a weight-loss plan (factor 1.0), 320 kcal/cup food → **0.88 cups/day** (100.6 g/day) • 4 lb kitten under 1 year (factor 2.5), 400 kcal/cup food → **0.68 cups/day** (78.7 g/day) **Worked example:** a 10 lb neutered adult cat converts to 4.54 kg. RER = 70 × 4.54^0.75 = **217.6 kcal**. Applying a neutered-adult factor of 1.2: MER = 217.6 × 1.2 = **261.1 kcal/day**. On a 350-kcal-per-cup food, that's 261.1 ÷ 350 = **0.75 cups per day**, or about **0.37 cups per feeding** split across two meals. Cats use noticeably lower life-stage factors than dogs at the same relative body size — a cat's typical maintenance factor tops out lower than a dog's, which is one reason directly copying a dog's feeding formula onto a cat overfeeds it. ## How to Use This Calculator Enter your cat's **body weight** in pounds. Choose the **life-stage / activity category** that best matches your cat — neutered/spayed adult is the most common default for a typical indoor companion cat. Enter the **calories per cup** from your specific food's label — for wet or canned food, use the calories per typical can or per 100g in the same field, adjusting the 'grams per cup' field to match your unit. Set the **feedings per day** to see the per-meal amount, not just the daily total. **Example input:** Weight = 14 lb • Life stage = Weight loss • Food = 320 kcal/cup • Feedings = 2. **Output:** RER = 280.0 kcal • MER = 280.0 × 1.0 = **280.0 kcal/day** • Portion = 280.0 ÷ 320 = **0.88 cups/day** (100.6 g/day), or **0.44 cups per feeding**. If you're also curious how your cat's age translates to human-equivalent years, the [dog & cat age to human years calculator](/calculators/dog-cat-age-human-calculator) uses AVMA-compliant, size-adjusted formulas. ## The Formula This Calculator Uses Everything here is transparent, standard veterinary nutrition math — not a proprietary formula. **Step 1 — Convert weight to kilograms.** Weight (kg) = Weight (lb) × 0.453592. **Step 2 — Resting Energy Requirement.** RER (kcal/day) = 70 × Weight (kg)^0.75. This formula is the same across species — it's the allometric relationship between body mass and resting metabolic rate. **Step 3 — Apply a life-stage factor.** MER (kcal/day) = RER × Factor. Commonly cited cat factors: 1.2 for a neutered adult, 1.4 for an intact adult, 1.0 for weight loss, roughly 1.2-1.4 for weight gain, and around 2.5 for kittens under a year old. **Step 4 — Convert to a food-specific portion.** Portion (cups/day) = MER ÷ Calories per cup. The same cat needs a different measured amount on two different foods, because calorie density differs between products. **Why cat factors run lower than dog factors:** cats are generally less active per unit of body weight than dogs in the categories veterinary references compare, and cat-specific studies underlying these commonly cited multipliers reflect that. Applying a dog's factor to a cat's weight will systematically overestimate the cat's calorie needs. ## Step-by-Step Worked Derivation Take the 10 lb neutered adult cat example and do it by hand. **Step 1.** 10 lb × 0.453592 = **4.54 kg**. **Step 2.** 4.54^0.75 ≈ **3.108**. RER = 70 × 3.108 = **217.57 kcal**. **Step 3.** MER = 217.57 × 1.2 = **261.08 kcal**. **Step 4.** Portion = 261.08 ÷ 350 = **0.75 cups**, or 0.75 × 115 g/cup ≈ **85.8 g**. **Step 5 — per feeding.** Split across 2 feedings: 0.75 ÷ 2 = **0.37 cups** (43 g) per meal. **Answer:** about 0.75 cups (85.8 g) per day, split into two 0.37-cup feedings. ## Why Indoor Cats Are Especially Easy to Overfeed Cat obesity is common, and the math behind this calculator explains part of why: a typical indoor, neutered adult cat's factor (1.2) is one of the lowest maintenance multipliers of any common pet feeding category, yet many commercial feeding charts use a single generic recommendation that doesn't distinguish an indoor neutered cat from a more active intact one. **A relatively small weight gain is proportionally large for a cat.** Because cats are small animals, an extra pound represents a much bigger percentage of total body weight than the same extra pound would for a large dog — a 10 lb cat gaining 2 lb has gained 20% of its body weight, a change that would be a much smaller percentage shift for a 65 lb dog. **Free-feeding (leaving food out all day) removes the portion control this calculator provides.** If a cat has constant access to food, the calculated daily portion is only meaningful if you actually measure and offer that specific amount rather than refilling an always-full bowl. **Weight-loss plans need a lower factor, not just a smaller cup measurement of the same food.** Using the weight-loss factor (1.0) is the mechanism for a deliberate, gradual reduction — cutting a cat's food sharply without veterinary guidance risks a serious condition called hepatic lipidosis in cats that stop eating enough, so any calorie reduction plan for an overweight cat should be paced and ideally vet-supervised. ## Realistic Scenarios **Scenario 1 — A typical indoor companion cat.** 10 lb neutered adult, 350 kcal/cup food, 2 feedings: **0.75 cups/day** (85.8 g/day), 0.37 cups per feeding. **Scenario 2 — A cat on a gradual weight-loss plan.** 14 lb cat, weight-loss factor of 1.0, 320 kcal/cup food, 2 feedings: **0.88 cups/day** (100.6 g/day) — note this is still a real, adequate calorie amount at the reduced factor, not a severe restriction. **Scenario 3 — A growing kitten.** 4 lb kitten under a year, factor 2.5, 400 kcal/cup food, 3 feedings: **0.68 cups/day** (78.7 g/day) split into three roughly 0.23-cup meals — proportionally much more food per pound of body weight than either adult scenario, reflecting growth demands. ## Common Feeding Mistakes • **Applying a dog's feeding factor to a cat.** Cat life-stage multipliers generally run lower than dog multipliers at comparable activity levels — using dog numbers overfeeds a cat. • **Free-feeding without measuring at all.** A calculated portion only controls calorie intake if it's actually measured and offered as a distinct amount, not left available indefinitely. • **Sharply restricting an overweight cat's food without a gradual plan.** Rapid calorie restriction in cats carries a real risk of hepatic lipidosis (fatty liver disease) — weight loss in cats should be gradual and ideally supervised by a veterinarian. • **Reusing a cup measurement across dry and wet food.** Wet food is far less calorie-dense per volume than dry kibble, so a 'cup' of one is not equivalent to a 'cup' of the other. • **Ignoring treats.** Treats and 'people food' contribute real calories that should count against the day's total, especially for a cat managing weight. ## What This Calculator Can and Cannot Do **It can:** • Estimate a starting daily calorie need using a standard veterinary RER/MER formula • Convert that calorie need into cups and grams for a specific food's calorie density • Split the daily portion across multiple feedings • Show how the portion would change under a different life-stage category **It cannot:** • Diagnose obesity, underweight, or any medical condition affecting nutritional needs • Safely design a rapid weight-loss plan — cats require gradual, ideally vet-supervised calorie reduction to avoid hepatic lipidosis risk • Account for medical conditions like hyperthyroidism or kidney disease that significantly change energy needs • Know your specific food's exact calorie content without you entering it correctly from the label **The honest summary:** this is a starting-point estimate built on standard formulas. Monitor your cat's actual body condition and weight trend over several weeks, and adjust the portion — or consult your veterinarian — based on real results rather than the formula alone. ## Final Summary **The formula worth remembering:** RER = 70 × (kg)^0.75. MER = RER × life-stage factor (roughly 1.0 to 2.5 for cats). Portion = MER ÷ food's kcal per cup. **Quick reference:** a 10 lb neutered adult cat on an average-calorie dry food needs roughly 0.7-0.8 cups per day; kittens need meaningfully more per pound, and weight-loss plans should be gradual, not severe. **The one thing to actually do:** measure the calculated portion rather than free-feeding, and re-check body condition every few weeks — especially for a cat on a weight-loss plan, where the pace of loss matters as much as the target. Related tools worth a look: the [dog food portion calculator](/calculators/dog-food-portion-calculator) for the same method applied to dogs, and the [dog & cat age to human years calculator](/calculators/dog-cat-age-human-calculator) for age-stage context. For the WSAVA-aligned RER/MER science, including the hepatic lipidosis risk specific to cats, see our [pet food portion guide](/blog/hobby/pet-food-portion-guide). ## Frequently asked questions ### How much food should I feed my cat? Start with RER = 70 × (weight in kg)^0.75, then multiply by a life-stage factor — about 1.2 for a neutered adult cat. A 10 lb neutered cat needs roughly 261 kcal per day, which is about 0.75 cups of a 350-kcal-per-cup food. ### What is RER in cat nutrition? Resting Energy Requirement — the calories a cat burns at rest, calculated as 70 × (body weight in kg) raised to the 0.75 power. It's the standard starting point before applying a life-stage multiplier to reach maintenance calories. ### Why do cats need less food per pound than dogs? Cat life-stage factors are generally lower than dog factors at comparable activity levels — a neutered adult cat's factor is around 1.2, versus about 1.6 for a neutered adult dog. Applying a dog's feeding formula to a cat's weight tends to overfeed it. ### Is it safe to put my cat on a diet? Weight loss in cats should be gradual and ideally supervised by a veterinarian. Rapid calorie restriction carries a real risk of hepatic lipidosis (fatty liver disease) in cats, which is why the weight-loss factor (around 1.0) still represents a real, adequate calorie amount rather than a severe cut. ### How much more should I feed a kitten compared to an adult cat? Kittens under about a year typically use a life-stage factor around 2.5, compared to roughly 1.2 for a neutered adult — more than double, per unit of body weight, reflecting the extra energy growth requires. ### Should I free-feed my cat or measure portions? Measuring is more reliable for weight management. A calculated portion only controls intake if it's actually measured and offered as a distinct amount — free-feeding (leaving food out all day) removes that control entirely. ### Does this work for wet or canned cat food? Yes, if you use the calories per typical can (or per 100g) in place of 'per cup,' and adjust the weight-per-unit field to match. Wet food is far less calorie-dense per volume than dry kibble, so don't reuse a dry-food cup measurement for wet food. ### Is this cat food calculator free? Yes — completely free, no registration, and no data leaves your browser. Every figure recalculates instantly as you change an input. ## Related concepts - **Resting Energy Requirement (RER)** — The calories an animal burns at complete rest, calculated as 70 × (body weight in kg)^0.75 — a standard starting point in veterinary nutrition for both cats and dogs. - **Life-stage / activity factor** — A multiplier applied to RER to estimate Maintenance Energy Requirement. Cat factors generally run lower than dog factors — from about 1.0 for weight loss to 2.5 for kittens. - **Hepatic lipidosis** — A serious liver condition that can develop in cats that stop eating adequately, including during overly aggressive calorie restriction — the reason feline weight-loss plans should be gradual and ideally vet-supervised. ## Related guides - [How Much Should You Feed Your Dog or Cat? The RER/MER Science](https://dothecalculation.com/blog/hobby/pet-food-portion-guide) — The WSAVA-aligned veterinary formula behind daily feeding amounts for dogs and cats, why life stage changes the number so much, and why cats need extra caution with weight loss. ## Related calculators - [Dog Food Portion Calculator](https://dothecalculation.com/calculators/dog-food-portion-calculator) — Calculate your dog's daily food portion in cups and grams from body weight, life stage, and your food's calorie density. - [Crochet Blanket Size & Yardage Calculator](https://dothecalculation.com/calculators/crochet-blanket-dimensions-calculator) — Calculate the yarn yardage, skein count, and finished blanket weight based on your stitch density, gauge, and yarn class. - [BMR Calculator](https://dothecalculation.com/calculators/bmr-calculator) — Estimate your basal metabolic rate (BMR) and daily calorie needs at rest based on your age, gender, height, and weight for accurate results. - [Calorie Calculator](https://dothecalculation.com/calculators/calorie-calculator) — Estimate your daily calorie needs for weight loss, maintenance, or muscle gain based on age, gender, height, weight, and activity level. - [Protein Calculator](https://dothecalculation.com/calculators/protein-calculator) — Estimate your ideal daily protein intake based on body weight, activity level, and fitness goals like building lean muscle. - [Adaptive TDEE Calculator](https://dothecalculation.com/calculators/tdee-adaptive-calculator) — Calculate your true adaptive TDEE using real-world daily calorie intake and weight trend data for more accurate results. --- _This calculator estimates a starting daily food portion using standard veterinary RER/MER formulas and commonly cited life-stage factors. It does not diagnose any condition, does not account for a specific cat's medical history (such as hyperthyroidism or kidney disease), and is not a substitute for guidance from a veterinarian — particularly for kittens, senior cats, cats with a medical condition, or any cat on a weight-loss plan, which should be paced gradually and ideally supervised by a vet._ --- _Source: [Do The Calculation](https://dothecalculation.com/calculators/cat-food-portion-calculator). Quote freely with attribution and a link to this page._