Puppy Weight Calculator: How Big Will My Dog Get?

A puppy does not grow at a steady rate, so you cannot simply double its weight and hope for the best. Small dogs finish growing at around a year, while large and giant breeds keep filling out until 18 to 24 months. This calculator estimates your puppy's adult weight by working out how far along its growth curve it already is, based on its current weight, age and the size it is expected to reach.

How this works: puppies of different sizes grow at different rates, so a four-month-old toy breed is far closer to its final weight than a four-month-old giant breed. The calculator reads off a typical growth curve for the size you choose to work out what percentage of its adult weight your puppy has already reached, then scales the current weight up from there. Treat the figure as a well-informed estimate, not a promise: nutrition, neutering, health and where your dog sits within its breed all shift the final number. Weigh your puppy every couple of weeks so you can spot any sudden gain or loss, and speak to your vet if the growth looks off.

Once you have a rough adult weight, our dog crate size calculator will tell you which crate to buy so you are not replacing it in six months, and the dog food portion calculator helps you feed the right amount as your puppy grows.