Free calculators, with the sources shown

Search for how big a puppy will get and you will find plenty of tools that hand you a number. Very few tell you where the number came from, and most put a suspiciously narrow range around it.

That matters, because these are estimates. A growth curve describes where most dogs land, not where yours will. A tool that hides the spread is not being more accurate, it is being less honest.

So the rule here is simple: if a figure is on the site, it has a source stored next to it in the code, and that source is printed at the bottom of the page. Where we could not find a source, the site says so and leaves the number out instead of filling the gap.

The growth model is the biggest piece. The published veterinary growth standard for dogs presents its charts as images, which cannot be copied, so we went to the open dataset released alongside it: just under 15 million weight records. From those we found the 339,119 dogs that had both puppy weights and adult weights, and measured how far along each one was at every week of age.

That gives two things. A middle estimate, and a real measured spread, which is why the range you see is wider at eight weeks than at a year rather than a flat percentage.

Breed weights and heights come from kennel club breed standards. Pregnancy and heat cycle figures come from the Merck Veterinary Manual. Grooming prices and tipping guidance come from published US sources, and where two of them disagree the site shows both rather than averaging the disagreement away.

The whole method is written out on the how we calculate page, including the handful of places where we have had to round something ourselves. Those are labelled as estimates wherever they appear.

We do not give veterinary advice, medication doses, or anything that would stand in for seeing a vet. Every tool says so. If something seems wrong with your animal, that is a question for someone who can examine it.

We do not ask for an account, an email address, or a payment. The calculators run in your own browser, so nothing you type into them is sent anywhere or stored.

We do not run advertising, and there are no paid or affiliate links on the site. If any are added later, each one will carry a visible label saying so.