Cat Calorie Calculator Singapore: How Much to Feed
It's 7pm in your HDB kitchen, your cat is doing the figure-eight around your ankles, and you're staring at the back of a food pack wondering if the feeding chart is actually right for your cat. The bag says 60g. The vet said "feed less." Your cat says "feed more, immediately."
Who's right?
None of them, fully. Cat feeding isn't about following the back of a pack. It's about knowing your cat's daily calorie target and working backwards. Once you know the number, the grams sort themselves out, whether you're on kibble, fresh food, or a mix.
Here's the maths Singapore pawrents actually need, plus a worked example you can copy for your own furkid.
Why Singapore cats are easy to over-feed
Most cats in Singapore are indoor cats. We live in HDB flats and condos, the climate makes outdoor roaming risky (heat, traffic, AVS rules), and our cats spend their day sleeping on the aircon vent rather than hunting lizards in a garden.
That changes the calorie equation. An indoor neutered adult cat burns roughly 20 to 30% fewer calories than an outdoor or intact cat of the same weight. Combine that with free-feeding kibble (calorie-dense, easy to over-pour) and you get the most common vet-room conversation in Singapore: "your cat is overweight."
Singapore's Cat Welfare Society and most local vet clinics flag the same trend. A 5kg domestic shorthair that should be 4kg is carrying 25% extra body weight, which is roughly the human equivalent of being 20kg overweight.
The fix isn't a crash diet. It's knowing the daily calorie target and feeding to it consistently.
The two formulas you actually need
Vets use two numbers: RER and MER.
RER (Resting Energy Requirement) is the calories a cat burns just existing, lying on the sofa, breathing, blinking. The formula:
`RER = 70 × (body weight in kg)^0.75`
That exponent (^0.75) is why you can't just multiply by a flat number per kilo. A 2kg kitten doesn't burn half the calories of a 4kg adult, it burns more per kg of body weight.
If you don't have a calculator that does exponents, here's the quick table:
- 2kg cat: RER ≈ 118 kcal
- 3kg cat: RER ≈ 160 kcal
- 4kg cat: RER ≈ 198 kcal
- 5kg cat: RER ≈ 234 kcal
- 6kg cat: RER ≈ 268 kcal
- 7kg cat: RER ≈ 300 kcal
- Neutered indoor adult: RER × 1.0 to 1.2
- Intact or active adult: RER × 1.2 to 1.4
- Weight loss target: RER × 0.8
- Weight gain / underweight: RER × 1.2 to 1.4 (see our weight gain guide for cats)
- Pregnant cat: RER × 1.6 to 2.0
- Lactating cat: RER × 2.0 to 6.0 (yes, really)
- Kitten under 4 months: RER × 2.5
- Kitten 4 to 12 months: RER × 2.0
- Senior (11+ years): RER × 0.8 to 1.0
Worked example: Mochi, 4kg indoor adult
Mochi is a 4kg spayed indoor cat, 5 years old, moderately playful (chases the laser pointer for ten minutes then naps for three hours).
1. RER = 70 × (4)^0.75 = 198 kcal
2. Lifestyle factor: indoor neutered = 1.0. Slightly active = bump to 1.1.
3. MER = 198 × 1.1 = 218 kcal per day
Now the food side. The Bon Pet gently cooked cat recipes sit around 1.3 to 1.5 kcal per gram depending on protein (kangaroo and beef run slightly higher, chicken slightly lower). Call it 1.4 kcal/g as a working average.
218 kcal ÷ 1.4 kcal/g = 156g per day.
Split across two meals, that's about 78g per meal, which lines up with the 65g × 2 + a small kibble top-up baseline we use in our cat feeding portion guide.
If Mochi was on dry kibble at 3.5 to 4 kcal/g, the same 218 kcal works out to only 54 to 62g of kibble. Tiny amount. This is exactly why cats on kibble get over-fed: the portion looks sad, so pawrents add a scoop.
Adjusting the number to real life
The formula gives you a starting point, not a verdict. You adjust based on what your cat's body and litter box tell you.
Body condition over the scale. Run your hands along your cat's ribs. You should feel them with light pressure, like the back of your hand. If you have to press in to find ribs, your cat is over the calorie target. If they feel sharp and prominent, under. Singapore vets use a 1 to 9 body condition score; 5 is ideal.
Weigh monthly, not daily. Cats fluctuate. A 0.1kg swing on a 4kg cat is 2.5% body weight, which can just be hydration or a recent meal. Weigh the same time, same day of month, on a kitchen scale (hold the cat, subtract your weight).
Stool tells you about portion, not just food quality. Loose stool on a new food usually means transition too fast (see our transition protocol). But persistent loose stool on a stable food can mean overfeeding.
Singapore-specific: water intake. Our climate is hot and humid. Cats on dry kibble in Singapore are chronically borderline dehydrated, which masks weight changes and stresses kidneys long-term. Fresh and gently cooked food is roughly 70 to 75% moisture (kibble is 8 to 10%), so cats on fresh food drink less but are better hydrated overall. Calorie maths is the same, but the hydration buffer is worth knowing.
Kittens, seniors, and the cats that break the formula
Kittens are calorie black holes. A 1kg 3-month-old kitten needs roughly 200 kcal a day, which is the same as a 4kg adult. They eat for growth, not maintenance. Feed three to four times daily, free-feed if you can stomach the mess, and don't restrict portions before 12 months unless your vet has flagged a problem.
Seniors (11+). Older cats lose muscle mass and often need more calories per kg, not less, despite being less active. This is counter-intuitive, but the underlying cause is reduced protein absorption. If your senior is dropping weight on the "correct" portion, the answer is usually more food and higher protein, not less. Our post on fresh food for senior pets walks through this.
Picky eaters. The calorie target doesn't change if your cat refuses to eat it. Cats that go more than 48 hours without food can develop hepatic lipidosis (fatty liver), which is a real medical emergency. If you're transitioning a picky cat to fresh food, don't fast them into compliance. Mix small portions in with their current food and increase slowly across 5 to 7 days.
What to do with this number now
Write it down. Stick it on the fridge. The single biggest reason cats end up overweight in Singapore isn't bad food, it's pawrents who genuinely don't know the number and rely on "a scoop" or "a pouch" without checking the calorie density on the back.
Once you have your cat's daily target:
1. Check the kcal/g on whatever food you're using (it's on every reputable label; our open formula sheets list it).
2. Divide target by kcal/g to get daily grams.
3. Split across two meals for adults, three to four for kittens.
4. Re-weigh your cat monthly and adjust by 5 to 10% in either direction.
Jia Wei, who feeds her sensitive-gut cat Mochi on our kangaroo, put it simply in her review: "Kangaroo from Bon Pet is the first food she's eaten consistently for 4 months straight. Life changing." Consistency is half the battle. The calorie target is the other half.
Try The Bon Pet without committing to a full pack
If you're moving from kibble to fresh and not sure which protein your cat will actually eat, our 4-protein cat trial pack lets you sample chicken, beef, duck, and kangaroo in 200g portions. Intro savings apply at checkout. Sous vide cooked at 80°C, AAFCO All Life Stages, PhD-formulated, delivered frozen by Ninja Van cold chain.
Weigh your cat. Run the numbers. Feed to the target. Your vet will notice at the next checkup.
❤️ The Bon Pet team
Frequently asked questions
How many calories does a 4kg cat need per day in Singapore?
About 200 to 220 kcal per day for a healthy spayed indoor adult cat. The exact number is RER (70 × 4^0.75 = 198 kcal) multiplied by 1.0 to 1.2 for indoor lifestyle. Active or intact cats need 240 to 280 kcal.
What's the formula to calculate my cat's daily calorie needs?
RER = 70 × (body weight in kg)^0.75. Then multiply by a lifestyle factor: 1.0 for indoor neutered adult, 1.2 to 1.4 for active, 2.0 to 2.5 for kittens, 0.8 for weight loss. That gives you MER, your cat's daily calorie target.
How many grams of fresh food should I feed my cat per day?
Divide your cat's daily calorie target by the kcal per gram of the food. The Bon Pet gently cooked cat recipes average 1.4 kcal/g, so a 4kg cat needing 220 kcal eats about 156g per day, split into two 78g meals.
Why do indoor cats in Singapore get overweight so easily?
Indoor neutered cats burn 20 to 30% fewer calories than outdoor or intact cats, and Singapore's climate means most pet cats are fully indoor. Free-feeding calorie-dense kibble on top of low activity pushes the average HDB cat 15 to 25% over ideal weight.
Should I feed kittens more calories than adult cats?
Yes. Kittens under 4 months need RER × 2.5 (roughly 200 kcal for a 1kg kitten, same as a 4kg adult). Feed three to four times daily and don't restrict portions before 12 months unless your vet advises it.
