Cat Feeding Calculator: How Much Should I Feed My Cat?
A cat’s daily food need comes down to calories, and calories come down to body weight, age and activity. This calculator uses the standard veterinary formula for resting energy requirement and applies the usual life-stage multipliers. Enter your cat’s weight and a few details to get a daily calorie target and the equivalent in dry and wet food.
A cat's daily food need comes down to calories, and calories come down to body weight, age and activity. This calculator uses the standard veterinary formula for resting energy requirement and applies the usual life-stage multipliers. Enter your cat's weight and a few details to get a daily calorie target and the equivalent in dry and wet food.
Dry food assumed at 3.8 kcal/g, wet food at 0.9 kcal/g — typical values. Check your own food's label: the calorie content is usually printed as kcal/kg or kcal/can, and it varies a lot between brands.
How this is calculated
The formula has two steps, and both are standard in veterinary nutrition.
Step 1 — resting energy requirement (RER). RER = 70 × (body weight in kg)0.75. This is the energy a cat needs at complete rest, just to maintain its body. The exponent is why the number does not scale linearly: a cat twice the weight does not need twice the calories.
Step 2 — apply a multiplier. A cat that is growing, active, pregnant or recovering needs more than its resting requirement; a neutered, sedentary indoor cat needs less. We multiply the RER by factors for life stage, activity, neuter status and whether the cat needs to lose or gain weight.
Why the multiplier matters more than the formula
Most online calculators stop at RER and then guess the multiplier, which is where the real error creeps in. The difference between a sedentary neutered indoor adult (around 0.85 × RER) and an entire, very active cat (around 1.15 × RER) is roughly 35% — the difference between a cat at a healthy weight and a cat slowly gaining. If you only remember one thing from this page, make it that.
Working out portions from calories
Food labels give energy in one of two ways:
| Label says | How to use it |
|---|---|
| kcal/kg (or ME kcal/kg) | Divide the daily kcal by this number, then × 1000 for grams. Example: 240 kcal/day ÷ 3,800 kcal/kg × 1000 = 63 g |
| kcal/can or kcal/pouch | Divide the daily kcal by the per-can figure. Example: 240 ÷ 80 = 3 cans |
If the label is in kilojoules (kJ), divide by 4.184 to get kcal. This trips people up constantly — a food labelled "1,600 kJ/100 g" is about 382 kcal/100 g, not 1,600.
How often should a cat be fed?
Adult cats do well on two meals a day, roughly twelve hours apart. Free-feeding dry food suits some cats but makes weight control much harder, because you cannot see how much has been eaten. If your cat is overweight, or you have more than one cat, scheduled meals in separate rooms are the practical answer — it is the only way to know which cat is eating what.
When the calculator will be wrong
Treat the number as a starting point and let the cat's body condition be the judge. Run your hands along the ribs: you should feel them easily under a thin layer of fat, without pressing. From above, there should be a visible waist behind the ribs. From the side, the belly should tuck up slightly. If the ribs are hard to find, the cat is carrying too much; if they are sharp and prominent with no covering, too little.
Weigh your cat on the same scale, at the same time of day, every two weeks. Adjust the daily amount by about 10% in the direction you need, then leave it for two weeks before adjusting again. Rapid changes are harder on the body than gradual ones.
Frequently asked questions
- How many calories does my cat need per day? A typical 4 kg neutered indoor adult needs roughly 200–250 kcal a day. Small cats need less, large breeds more. Use the calculator above for a figure based on your cat's actual weight and lifestyle.
- Is wet food better than dry? Wet food carries more water, which matters for cats because they are poor drinkers and dehydration contributes to urinary and kidney problems. Dry food is cheaper and more convenient. Many owners feed both — see our comparison in water fountain vs bowl.
- Should I free-feed my cat? It works for some cats and makes weight control harder for most. If you have more than one cat, or any cat is overweight, scheduled meals are far easier to manage.
- My cat always seems hungry — am I underfeeding? Not necessarily. Cats ask for food for many reasons, including boredom. Judge by body condition and weight trend, not by how loudly the cat asks.
- Do kittens need more food than adults? Yes, substantially — growing kittens need roughly two to three times an adult's calories per kilogram. Feed kitten-formulated food and follow the label until around twelve months.
How this is calculated
The formula has two steps, and both are standard in veterinary nutrition.
Step 1 — resting energy requirement (RER). RER = 70 × (body weight in kg)0.75. This is the energy a cat needs at complete rest, just to maintain its body. The exponent is why the number does not scale linearly: a cat twice the weight does not need twice the calories.
Step 2 — apply a multiplier. A cat that is growing, active, pregnant or recovering needs more than its resting requirement; a neutered, sedentary indoor cat needs less. We multiply the RER by factors for life stage, activity, neuter status and whether the cat needs to lose or gain weight.
Why the multiplier matters more than the formula
Most online calculators stop at RER and then guess the multiplier, which is where the real error creeps in. The difference between a sedentary neutered indoor adult (around 0.85 × RER) and an entire, very active cat (around 1.15 × RER) is roughly 35% — the difference between a cat at a healthy weight and a cat slowly gaining. If you only remember one thing from this page, make it that.
Working out portions from calories
Food labels give energy in one of two ways:
| Label says | How to use it |
|---|---|
| kcal/kg (or ME kcal/kg) | Divide the daily kcal by this number, then × 1000 for grams. Example: 240 kcal/day ÷ 3,800 kcal/kg × 1000 = 63 g |
| kcal/can or kcal/pouch | Divide the daily kcal by the per-can figure. Example: 240 ÷ 80 = 3 cans |
If the label is in kilojoules (kJ), divide by 4.184 to get kcal. This trips people up constantly — a food labelled “1,600 kJ/100 g” is about 382 kcal/100 g, not 1,600.
How often should a cat be fed?
Adult cats do well on two meals a day, roughly twelve hours apart. Free-feeding dry food suits some cats but makes weight control much harder, because you cannot see how much has been eaten. If your cat is overweight, or you have more than one cat, scheduled meals in separate rooms are the practical answer — it is the only way to know which cat is eating what.
When the calculator will be wrong
Treat the number as a starting point and let the cat’s body condition be the judge. Run your hands along the ribs: you should feel them easily under a thin layer of fat, without pressing. From above, there should be a visible waist behind the ribs. From the side, the belly should tuck up slightly. If the ribs are hard to find, the cat is carrying too much; if they are sharp and prominent with no covering, too little.
Weigh your cat on the same scale, at the same time of day, every two weeks. Adjust the daily amount by about 10% in the direction you need, then leave it for two weeks before adjusting again. Rapid changes are harder on the body than gradual ones.
Frequently asked questions
- How many calories does my cat need per day? A typical 4 kg neutered indoor adult needs roughly 200–250 kcal a day. Small cats need less, large breeds more. Use the calculator above for a figure based on your cat’s actual weight and lifestyle.
- Is wet food better than dry? Wet food carries more water, which matters for cats because they are poor drinkers and dehydration contributes to urinary and kidney problems. Dry food is cheaper and more convenient. Many owners feed both — see our comparison in water fountain vs bowl.
- Should I free-feed my cat? It works for some cats and makes weight control harder for most. If you have more than one cat, or any cat is overweight, scheduled meals are far easier to manage.
- My cat always seems hungry — am I underfeeding? Not necessarily. Cats ask for food for many reasons, including boredom. Judge by body condition and weight trend, not by how loudly the cat asks.
- Do kittens need more food than adults? Yes, substantially — growing kittens need roughly two to three times an adult’s calories per kilogram. Feed kitten-formulated food and follow the label until around twelve months.