Who made this
Not a vet.
Just bad at trusting a scoop.
My name is Alexandre. I built this because I weighed my dog's food one evening and the numbers stopped agreeing with each other.
The part most sites skip
You don't get my surname or my face
First name only, and no photograph of me. That is a deliberate choice about my own privacy, and you should treat it as a reason to be more sceptical, not less. A health-adjacent site that won't tell you who wrote it has given up the easiest way of earning your trust.
So here is the trade I'm offering instead. I am not asking you to trust a person.Every number this site produces is published with the formula that made it and the primary source behind that formula — you can check the arithmetic without knowing anything about me, which is more than you can do with most bylines.
What I will not do is invent a person to fill the gap. There is no stock photo here, no fabricated nutritionist, and no borrowed credential. An anonymous author is a weakness. A made-up one is a lie, and it is the more common of the two.
Credentials, or the absence of them
I am not a veterinarian
I have no veterinary qualification of any kind, and nothing on this site is veterinary advice. I cannot examine your animal and I do not know anything about it that you have not typed in.
I am not a nutritionist
Every constant in the engine is lifted from published veterinary sources and labelled with where it came from. None of it is my opinion. Where the research does not support a number, the tool refuses rather than estimating one.
What I actually am
Someone who writes software and owns a dog. The first part means I can read a formula, test it, and notice when it disagrees with itself. The second part is why I cared enough to.
This is not a business
No company, no ads, no affiliate links, nothing to sell you, and no pet food manufacturer has any involvement in it. The calculator is free and stays free. If that ever changes, this page will say so.
The dog this started with
His name is Ultra
He is a golden retriever, and he was carrying more than he should have been. I had been feeding him the way everybody feeds a dog: a scoop, twice a day, roughly the same as last time. When I finally put the food on a kitchen scale it came to about440 g a day.
Then I read the back of the bag properly. Purina's own printed guide for that food recommends 410–485 g a day for a dog between 35 and 45 kg. So the scoop and the manufacturer agreed with each other almost exactly. Everyone was doing what they were told, and the dog was still overweight.
The number that convinced me the maths was worth publishing. My vet had independently put Ultra's lean weight at 38.5 kg. When I ran him through the engine at 42 kg with a body condition score of 6, the ideal weight it derived — from the score alone, having never been told what the vet said — came out at 38.18 kg. Three hundred and twenty grams apart.
That is one dog. It is not proof the formula is right, and I have been careful not to write it up as though it were — one agreement is an anecdote, and this site says so on the pages where it matters. But it was enough to make me stop treating the arithmetic as a private curiosity.
One thing I want to be exact about, because it would be easy and dishonest to blur:the bag was not lying to me. Its guide is a maintenance figure for a dog at that weight, and as a maintenance figure it was about right. A weight-loss ration is deliberately below maintenance. Comparing the two and calling the difference a manufacturer's error is a trick, and I would rather not do the trick.
Instead of trusting me
01
Read the working
How it works lists every formula, every multiplier and the source it came from — including the places where the published research does not agree with itself.
02
Watch what it refuses
The tool declines to produce a plan for a pregnant, growing, very young or unwell animal, and it will not guess a calorie density it cannot derive. A refusal is the part of a calculator nobody fakes.
03
Check the founding claim
Cups are lying to youcites both studies with their DOIs — and discloses that one of them was funded by a pet food manufacturer, because you should know that before you weigh it.
And if a number this site gives you looks wrong, that is the message I most want to receive. Real people using it have already changed the engine more than once.Tell me — but talk to your vet before you change what you feed.