Puppy Size Predictor

Free puppy growth calculator

How big will your puppy get?

See your puppy’s predicted adult weight, height, size class, and growth timeline—then share the result.

100-breed modelPrivate by designRange, not guesswork
1 Tell us about your puppy
Paw size compared with their body

Pick the option that feels most like your pup.

Improve your prediction Add parent details, sex, and body condition

Parent weights have the strongest effect here. Use known adult weights rather than guesses.

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The honest version

A better puppy size estimate uses more than one shortcut.

“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

When do dogs stop growing?

Height usually settles before a young dog finishes filling out. Larger dogs generally need more time.

XS

Toy dogs

8–12 months

Fast early growth, with most adult height reached within the first year.

S

Small dogs

10–12 months

Often close to adult weight around their first birthday.

M

Medium dogs

12–15 months

May gain muscle and body condition after height growth slows.

L

Large dogs

15–18 months

Longer, steadier development makes early estimates less precise.

XL

Giant dogs

18–24 months

Can continue maturing into their second year.

Improve your estimate

Four clues worth using together

  1. 01

    Current age and weight

    Recent, accurately measured numbers give the growth curve a stronger starting point.

  2. 02

    Breed or likely size

    Adult size changes how quickly a puppy reaches each stage of growth.

  3. 03

    Parents’ adult weights

    If known, the parents are often more informative than paw size or loose skin.

  4. 04

    Healthy body condition

    An underweight or overweight puppy can distort a weight-only projection.

Common questions

Puppy size predictor FAQ

How can I estimate how big my puppy will get?

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.

When do puppies stop growing?

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.

Is the puppy weight calculator exact?

No calculator can account for every genetic and health factor. This is an educational planning estimate, not veterinary advice or a guarantee.

Does paw size predict adult dog size?

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.

Can I use this for a mixed-breed rescue puppy?

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.

Why did my puppy’s estimate change?

Growth is uneven. Rechecking every four weeks with an accurate weight can produce a more stable estimate as your puppy gets older.

Keep growth healthy, not fast.

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.