GagPetCalculator started with a simple frustration — the bag said "feed 2 cups a day" but nobody could explain why. We built the tool every pet owner deserves: one that actually explains the science in plain English.
It was 2025. Dr. Sarah Mitchell had just finished her third consultation of the day — a Labrador named Biscuit who had quietly put on 6kg over two years. The owner was devastated. She had been following the feeding instructions on the bag. She'd done everything right. Or so she thought.
The instructions on pet food bags are written for the most active, heaviest version of your pet. They don't account for age, spaying, indoor lifestyle, or the extra treats your kids sneak under the table. For most dogs and cats, following the bag means chronic mild overfeeding — and over months and years, that adds up to real health problems.
Sarah called her old university friend James Rivera, a software engineer who'd just adopted a pair of British Shorthair cats and was facing the same confusion. Together with animal science researcher Dr. Emma Clarke, they spent six months building the calculator they wish had existed all along.
GagPetCalculator launched in early 2026 with one simple promise: give every pet owner the same quality of nutrition guidance that a veterinary nutritionist would provide, completely free. Today, more than 50,000 pet owners use GagPetCalculator every month. Biscuit, we're told, lost the weight and is doing wonderfully.
To make professional-grade pet nutrition advice accessible to every single pet owner — regardless of budget, location, or experience level. Your pet's health shouldn't depend on whether you can afford a specialist consultation. We believe the basic science should be free for everyone.
Every formula in our calculator is grounded in veterinary nutritional science. We update our formulas whenever new research is published. No fads, no guesswork — just evidence.
We don't let advertisers influence our recommendations. If we suggest a food brand, it's because our team genuinely believes it's good for your pet — not because they paid us.
The core calculator will always be free. Good nutrition guidance shouldn't be gated behind a subscription or a $200 vet consultation for something you can learn in 2 minutes.
We translate complex veterinary science into simple, clear language. No jargon, no confusing charts. Just practical advice you can actually use today.
We don't sell your data. We don't store identifiable information from your calculator sessions. What you tell us about your pet stays between you and your screen.
We believe in sustainable pet ownership — including not overfeeding, which creates unnecessary food waste. Proper portions are good for your pet and the planet.
Three people who turned a shared frustration into something that helps thousands of pets live healthier lives.
Sarah has 14 years of clinical veterinary experience, with a specialist focus on small animal nutrition. She's the brain behind our feeding formulas and writes many of our nutrition guides. She has two Border Collies named Pixel and Scout.
James spent eight years building consumer health apps before co-founding GagPetCalculator. He built the original calculator over a long weekend after one of his British Shorthairs, Mr. Flops, was diagnosed as obese. He now has two very healthy cats.
Emma holds a PhD in comparative animal nutrition from the University of Edinburgh. She reviews all our scientific content for accuracy and leads our research partnerships with veterinary universities. She is owned by a very opinionated Maine Coon called Duchess.
Pet obesity is an epidemic. 56% of US dogs and 60% of US cats are overweight or obese — and the leading cause is overfeeding from inaccurate guidelines. We built GagPetCalculator to give every pet owner the information they need to feed their animal the right amount. Every day.
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