In-depth guide · Growth
How big will my puppy get? What real growth data shows
How to estimate your puppy’s adult weight from its weight, age and size class, with honest ranges, a worked example and why calculators disagree.
Growth
Puppy growth chart & weigh-in tracker
Up to 12 weigh-ins on centile lines from open veterinary data, with the weekly gain and a flag when the curve crosses lines.
Weigh-in tracker
Example4 weigh-ins, male, large size class (66–88 lb adults)
Centile · latest weigh-in, 26 weeks
about the52nd
At 26 weeks, 50 lb is between the 50th and 75th centile lines for male puppies in the large class (66–88 lb adults).
- Lines crossed
- 0since 12 weeks
- Latest gain
- +2.33 lb/wk+1,059 g a week
- Adult estimate
- about 73 lbhalf end 67–81 lb
No flag: the latest weigh-in sits as many lines up as the first one from 12 weeks.
Sources checked How the math works Data and sources
- Crossing 1: Crossed the 50th line going down, between 12 and 16 weeks.
- Crossing 2: Crossed the 50th line going up, between 20 and 26 weeks.
- his weigh-ins
- centile lines, 2nd to 98th
- a line crossed (numbered)
Growth bands derived by Puppy Scale from Salt C et al. (2017), PLOS ONE 12(9):e0182064, data: University of Liverpool DataCat 377, licensed CC BY 4.0. Our tables are empirical summaries, not the published model curves. Changes: see the method.
- 12 wkweigh-in 120 lb (9.1 kg) — between the 50th and 75th centile lines, about the 52nd
- 16 wkweigh-in 227 lb (12.2 kg) — between the 25th and 50th centile lines, about the 33rd+1.75 lb a week (+794 g a week)
- 20 wkweigh-in 336 lb (16.3 kg) — between the 25th and 50th centile lines, about the 37th+2.25 lb a week (+1,021 g a week)
- 26 wkweigh-in 450 lb (22.7 kg) — between the 50th and 75th centile lines, about the 52nd+2.33 lb a week (+1,059 g a week)
| Age | Weight (lb) | Weight (kg) | Centile band | Weekly gain |
|---|---|---|---|---|
| 12 wk | 20 | 9.1 | between the 50th and 75th centile lines (about the 52nd) | — |
| 16 wk | 27 | 12.2 | between the 25th and 50th centile lines (about the 33rd) | +1.75 lb (+794 g) |
| 20 wk | 36 | 16.3 | between the 25th and 50th centile lines (about the 37th) | +2.25 lb (+1,021 g) |
| 26 wk | 50 | 22.7 | between the 50th and 75th centile lines (about the 52nd) | +2.33 lb (+1,059 g) |
Talk to your vet. This is an estimate, not veterinary advice. Puppy Scale is not a veterinary practice and can’t examine your pet.
Estimate by Puppy Scale · sources checked October 7, 2026 · not veterinary advice · puppyscale.com
How the math works
Each rule below with its data and the date we read it. The example is a male puppy of the large size class weighed at 12, 16, 20 and 26 weeks.
- The centile lines
For each size class and sex, the 2nd, 9th, 25th, 50th, 75th, 91st and 98th centile of real weights at each week of age from 12 to 104 weeks, in intact and neutered dogs together; straight lines between weeks.
These are our empirical summaries of the same open data the published growth standards were built from — not the published model curves.
Growth standard charts for monitoring bodyweight in dogs of different sizes (PLOS ONE 12(9):e0182064), read · Growth standard charts for monitoring bodyweight in dogs of different sizes - SUPPORTING DATA, read
- Centile of a weigh-in
Which two lines the weight falls between, and an approximate centile by a straight line between those two lines. Example: 20 lb at 12 weeks is between the 50th and 75th centile lines, about the 52nd.
The band is the result; the number is a guide.
- Lines crossed
The number of lines below the latest weigh-in minus the number below the first weigh-in from 12 weeks. Two or more is flagged: fewer than 5% of healthy puppies cross more than two centile lines.
Patterns of growth in dogs, including centile crossing (Salt et al. 2020), read
- The numbered flags
Each place where the straight line between two weigh-ins meets a centile line, numbered by age and named in words below the chart.
- Flat growth
A weigh-in no heavier than an earlier one, before the age at which the median dog of the class reaches 95% of adult weight (weeks: toy 88 · small 72 · medium 84 · medium-large 80 · large 72 · giant 78).
Growth standard charts for monitoring bodyweight in dogs of different sizes (PLOS ONE 12(9):e0182064), read · Patterns of growth in dogs, including centile crossing (Salt et al. 2020), read
- Weekly gain
The difference between two weigh-ins divided by the weeks between them, from whole grams.
- Adult estimate
From the latest weigh-in, by the puppy weight calculator’s method (today’s weight ÷ the median share of adult weight at that age).
What this doesn’t cover
Breed-specific charts: Not modeled — no openly licensed breed curves exist; the chart uses the size class (checked October 7, 2026).
The published model curves: Not modeled — we use empirical summaries of the same open data instead (checked October 7, 2026).
Neutered-only charts: Not modeled — in the study neutering shifted growth only slightly next to the differences between dogs (checked October 7, 2026).
Weigh-ins before 12 weeks: Not modeled — they are plotted but get no centile, because the charts start at 12 weeks (checked October 7, 2026).
After 104 weeks: Not modeled — a dog is an adult — body condition, not growth lines, is the measure (checked October 7, 2026).
Data licences
Growth bands derived by Puppy Scale from Salt C et al. (2017), PLOS ONE 12(9):e0182064, data: University of Liverpool DataCat 377, licensed CC BY 4.0. Our tables are empirical summaries, not the published model curves. Changes: see the method.