Puppy Growth Stages Explained
How fast a puppy grows — and how long they keep growing — depends almost entirely on their expected adult size. A Chihuahua and a Great Dane are on completely different timelines, even though both are "puppies" for their first year or more.
General growth timeline by size
| Adult size | Reaches ~75% of adult weight | Growth essentially complete |
|---|---|---|
| Small (under 25 lb) | ~5-6 months | 9-10 months |
| Medium (25-50 lb) | ~6-7 months | 12 months |
| Large (50-90 lb) | ~7-9 months | 15-18 months |
| Giant (90+ lb) | ~9-12 months | 18-24 months |
If you want a live estimate rather than a general table, ourPuppy Weight Predictoruses these same growth curves to estimate your specific puppy's adult weight from their current weight and age.
Key stages
0-8 weeks: Neonatal and early socialization
Rapid early growth, still with the litter and mother in most cases. Not typically a stage you'll be tracking weight for yourself unless you're the breeder.
8-16 weeks: Fastest visible growth
This is when growth is most dramatic and visible week to week, especially in large and giant breeds. Overfeeding during this window is a known risk factor for developmental orthopedic problems in large breeds — this is exactly why large-breed puppy formulas exist and why "fatter puppy" is not the goal.
4-8 months: Steady growth, size differentiation becomes clear
By this point you can usually tell whether you have a small, medium, large, or giant dog on your hands. Small breeds are approaching adult size; large and giant breeds still have significant growing left.
8-24 months: Filling out
Height growth slows or stops, but many dogs — especially large and giant breeds — continue to "fill out" with muscle and chest depth well after they've stopped getting taller. This is why a large-breed dog can look adult-sized at 10 months but keep changing shape until 2 years old.
Insure while growth-related risk is still unknown
Hip and elbow dysplasia, common in large and giant breeds, typically doesn't show clear signs until later in growth. Insuring during the early growth window means these conditions are more likely to be covered if they do appear.
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What to adjust as your puppy grows
- Food amount — recalculate roughly every 4-6 weeks during rapid growth using ourfood calculator, since a fixed daily amount will under- or over-feed a fast-growing puppy within weeks.
- Crate and gear sizing — buying for current size instead of predicted adult size is the most common (and expensive) mistake with large and giant breeds.
- Exercise intensity — high-impact exercise (long runs, jumping) is generally discouraged for large-breed puppies until growth plates close, to protect developing joints.
For more on feeding choices during this window, see our guide onbest dog food by size and breed, and for large or giant breeds specifically, ourlarge breed care guidecovers joint health considerations in more depth.