Buyer Education
How to Use Our Puppy Weight Calculator: Estimating Adult Dog Size
Our free puppy weight calculator uses your puppy's current weight and age to estimate adult size. Here's exactly how it works, how accurate it is, and what affects the results.
September 27, 2026 · 5 min read
How the Calculator Works
Our Puppy Weight Calculator takes your puppy's current weight and age (in weeks) and applies breed-adjusted growth curve data to project adult weight. Small breeds grow faster relative to their adult size — reaching most of their adult weight by 9–10 months. Large breeds may not reach full adult weight until 18–24 months.
Breed Growth Categories
- Toy breeds (under 10 lbs adult): Yorkie, Toy Poodle, Biewer Terrier, Maltipoo
- Small breeds (10–25 lbs adult): Cavapoo, Cockapoo, Shihpoo
- Medium breeds (25–50 lbs adult): French Bulldog, Miniature Poodle
- Large breeds (50+ lbs adult): Standard Poodle, Goldendoodle
How Accurate Is the Estimate?
For pure breeds and well-known hybrids, our calculator is typically accurate within 10–15% of actual adult weight. Individual variation within the same litter is real — litter siblings can vary by 1–2 lbs at adulthood.
When to Use Puppy Weight for Estimation
- 8-week weight is the earliest reliable data point
- 12-week estimates are more accurate
- 16-week estimates are quite reliable for small and toy breeds
- Serial measurements tracking growth over time are more accurate than single-point projections
Try our free Puppy Weight Calculator at starstruckpuppies.com/puppy-weight-calculator for an instant adult weight estimate.