Puppy Weight Calculator
Find out how big your puppy will get. Predict their adult weight by breed size, current age, and current weight — with a growth timeline, milestone tracker, and breed comparison guide.
Puppy Weight Calculator
Enter your puppy’s details to predict their adult size
Medium: Border Collie, Cocker Spaniel, Beagle — adult weight 10–25 kg
Most accurate between 8 weeks and 6 months old
Weigh your puppy on a bathroom scale for best accuracy
Males tend to be 10–15% heavier than females in the same breed
Adult Weight Prediction
Estimated adult size and growth milestones
Enter your puppy’s breed size, age, and current weight, then click Predict Adult Weight to see how big they’ll grow and track their development milestones.
Dog Sizes Explained
Adult weight ranges and typical breeds for each size category.
Puppy Weight by Age
Expected weight ranges at key growth stages for each breed size category.
| Age | Toy (kg) | Small (kg) | Medium (kg) | Large (kg) | Giant (kg) |
|---|---|---|---|---|---|
| 8 weeks | 0.3–0.8 | 0.8–1.8 | 2–5 | 5–12 | 8–18 |
| 12 weeks | 0.6–1.2 | 1.5–3 | 4–9 | 10–20 | 16–32 |
| 4 months | 0.9–1.8 | 2–4 | 6–12 | 15–28 | 24–44 |
| 6 months | 1.5–2.8 | 3–6 | 8–16 | 20–36 | 32–58 |
| 9 months | 1.8–3.5 | 4–8 | 10–20 | 24–42 | 40–70 |
| 12 months | 2–5 | 5–10 | 12–25 | 26–44 | 46–80 |
| Adult (full grown) | 2–5 | 5–10 | 10–25 | 25–45 | 45–90+ |
Puppy Weight FAQ
Everything you need to know about puppy growth and adult weight prediction.
The most common formula for predicting adult weight is: Adult Weight = (Current Weight / Age in weeks) × 52, adjusted by a breed-size multiplier. For small breeds, puppies reach full size at around 10–12 months. Medium breeds finish growing at 12–15 months. Large and giant breeds can take 18–24 months. Our calculator uses breed-size-specific growth curves for the most accurate prediction.
Puppies stop growing at different ages depending on their breed size. Toy and small breeds (Chihuahua, Pomeranian) are fully grown by 10–12 months. Medium breeds (Cocker Spaniel, Border Collie) finish at 12–15 months. Large breeds (Labrador, German Shepherd) reach full size at 15–18 months. Giant breeds (Great Dane, Saint Bernard) may continue growing until 18–24 months.
For small breeds: Adult Weight ≈ Current Weight at 6 weeks × 4. For medium breeds: Adult Weight ≈ Current Weight at 14 weeks × 2.5. For large breeds: Adult Weight ≈ Current Weight at 16 weeks × 2. These are approximations; the most reliable prediction comes from knowing the weight of the puppy’s parents. Our calculator combines breed-size growth curves with current weight data for the best estimate.
At 8 weeks, expected weights vary widely by breed. Toy breeds typically weigh 0.3–0.8 kg. Small breeds weigh 0.8–1.8 kg. Medium breeds weigh 2–5 kg. Large breeds weigh 5–12 kg. Giant breeds can weigh 8–18 kg or more. Individual puppies within a litter can vary by up to 30%, so use these as a guide rather than a strict standard.
A healthy puppy should have ribs that are easily felt but not visibly prominent. You should see a slight waist when viewed from above, and the abdomen should tuck up slightly from the side. If ribs are very prominent, the puppy may be underweight. If you cannot feel the ribs at all, they may be overweight. Always consult your vet for a professional body condition score (BCS) assessment, as this is more reliable than weight alone.
Yes, breed size is the single biggest predictor of growth rate and final adult size. Smaller breeds grow faster relative to their adult size and reach maturity earlier. Giant breeds have a much longer growth period and put on weight more slowly as a percentage of their final size. Mixed-breed dogs typically follow the growth pattern of their dominant breed, though predicting adult size can be more difficult without a DNA breed test.
Yes. Large and giant breed puppies should be fed a large breed puppy formula that controls calorie intake and calcium-to-phosphorus ratios to prevent too-rapid bone growth, which can cause joint problems. Small and toy breed puppies need more frequent meals with calorie-dense food to prevent hypoglycaemia. Always follow your vet’s guidance and use the feeding guidelines on breed-appropriate puppy food.