Estimate your puppy’s likely adult weight range using breed category, current age, and weight. Enter a few details for a practical growth estimate.
Breed Size Estimator
Estimate your puppy’s likely adult weight range based on breed category, current age, and current weight.
Puppy Details
Adult Size Estimate
Approximate Growth Progress (by weight)
This bar reflects weight only, not skeletal maturity. Puppies gain weight faster than height, so a puppy at “70% of adult weight” is not necessarily 70% “grown.”
Breed Size Reference
| Category | Adult Weight | Adult Height | Growth Completes |
|---|---|---|---|
| Toy | 1–5 kg (2–11 lb) | 15–25 cm | 6–9 months |
| Small | 5–12 kg (11–26 lb) | 25–40 cm | 9–12 months |
| Medium | 12–25 kg (26–55 lb) | 40–55 cm | 12–15 months |
| Large | 25–45 kg (55–100 lb) | 55–70 cm | 15–18 months |
| Giant | 45–90+ kg (100–200+ lb) | 70–90 cm | 18–24 months |
Important: These estimates are based on generalized growth fractions for each breed category — not breed-specific growth charts. Individual puppies vary widely due to genetics, nutrition, and sex. Mixed breeds can fall between categories or outside them entirely. Use this as a rough guide, monitor body condition, and consult your veterinarian for personalized growth tracking.
How It Works
This estimator uses generalized growth fractions for each breed-size category. The core idea: a puppy at a given age has typically reached a certain fraction of its adult weight. These fractions are hand-built approximations of typical breed-size patterns, not a published clinical dataset.
Growth fractions (approximate)
· Toy: 8 wks ≈ 25% · 12 wks ≈ 40% · 16 wks ≈ 55% · 6 mo ≈ 80% · 9 mo ≈ 95%
· Small: 8 wks ≈ 20% · 12 wks ≈ 33% · 16 wks ≈ 48% · 6 mo ≈ 75% · 12 mo ≈ 95%
· Medium: 8 wks ≈ 15% · 12 wks ≈ 25% · 16 wks ≈ 38% · 6 mo ≈ 65% · 12 mo ≈ 88%
· Large: 8 wks ≈ 12% · 12 wks ≈ 20% · 16 wks ≈ 30% · 6 mo ≈ 55% · 12 mo ≈ 80%
· Giant: 8 wks ≈ 10% · 12 wks ≈ 16% · 16 wks ≈ 24% · 6 mo ≈ 45% · 12 mo ≈ 70%
Adult weight projection
adult weight ≈ current weight ÷ growth fraction at current age
(with a small gender adjustment — see below)
Example
Large breed puppy, 12 weeks, 8 kg, male
growth fraction at 12 wks ≈ 20%
raw projection ≈ 8 ÷ 0.20 = 40 kg
male adjustment ≈ ×1.025 (half the dimorphism applied to the fraction)
≈ 41 kg
Gender adjustment
Males are typically ~5–10% heavier than females within a breed category. This estimator applies a small ±2.5% adjustment. Note: this is a statistical nudge — if your puppy is already tracking larger or smaller than average, that signal is already captured in the current weight.
Weight conversion
1 kg = 2.20462 lb
Why growth curves differ: Small breeds mature faster — a Toy breed puppy at 6 months is nearly adult-sized. Giant breeds grow slowly over 18–24 months, which is why their early growth fractions are lower. This calculator accounts for these broad differences but cannot capture breed-specific or individual variation.