Toy dogs
8–12 monthsFast early growth, with most adult height reached within the first year.
Free puppy growth calculator
See your puppy’s predicted adult weight, height, size class, and growth timeline—then share the result.
Estimated adult size
The honest version
“Double the weight at 16 weeks” is memorable, but it treats every dog as if it grows at the same speed. Toy breeds mature much sooner than giant breeds. This calculator uses a growth curve matched to the expected adult size, then blends it with a typical breed range when a breed is known.
The result is deliberately a range. Sex, parent size, nutrition, health, and mixed ancestry can all move the final number. For the best real-world estimate, compare this result with your veterinarian’s body-condition assessment and the adult weights of both parents.
Read the complete methodology →Puppy growth guide
Height usually settles before a young dog finishes filling out. Larger dogs generally need more time.
Fast early growth, with most adult height reached within the first year.
Often close to adult weight around their first birthday.
May gain muscle and body condition after height growth slows.
Longer, steadier development makes early estimates less precise.
Can continue maturing into their second year.
Improve your estimate
Recent, accurately measured numbers give the growth curve a stronger starting point.
Adult size changes how quickly a puppy reaches each stage of growth.
If known, the parents are often more informative than paw size or loose skin.
An underweight or overweight puppy can distort a weight-only projection.
Common questions
Use current age and weight together with breed or expected adult size. The younger the puppy and the less you know about its parents, the wider the reasonable range should be.
Toy and small dogs often approach adult size in their first year. Medium dogs may mature around 12–15 months, large dogs around 15–18 months, and giant breeds can keep filling out until roughly 18–24 months.
No calculator can account for every genetic and health factor. This is an educational planning estimate, not veterinary advice or a guarantee.
It can be a clue, especially when paws look unusually large for the body, but it is unreliable by itself. Age, weight, breed, and parent size are stronger inputs.
Yes. Choose “Mixed / unknown breed,” then select the size class that best fits shelter guidance, DNA results, or the known parent. Expect a wider range when ancestry is uncertain.
Growth is uneven. Rechecking every four weeks with an accurate weight can produce a more stable estimate as your puppy gets older.
If your puppy is losing weight, growing unusually quickly, limping, or has a pot-bellied appearance, ask a veterinarian rather than relying on a calculator.