Affiliate Disclosure: PetHub Online is reader-supported. When you buy through links on our site, we may earn an affiliate commission at no extra cost to you. This helps us continue providing free, research-backed pet care content. Learn more.
Quick Answer: Puppy growth rates vary significantly by breed size. Small breeds reach adult weight by 9-12 months, medium breeds by 12-14 months, large breeds by 14-18 months, and giant breeds by 18-24 months. A healthy puppy should gain weight steadily without becoming overweight. Use breed-specific growth charts and regular vet weigh-ins to track progress.
Table of Contents
- At A Glance
- Understanding Puppy Growth Patterns
- Small Breed Growth Chart (Adult Weight Under 10kg)
- Medium Breed Growth Chart (Adult Weight 10-25kg)
- Large and Giant Breed Growth Chart (Adult Weight Over 25kg)
- How to Weigh Your Puppy at Home
- Comparison Table
- Common Mistakes to Avoid
- What To Do Next
- Key Terms
- Frequently Asked Questions
- Recommended Products
- Sources & References
What Is the At A Glance?
- Small breeds grow fastest, reaching adult size by 9-12 months
- Giant breeds grow slowest, not reaching full size until 18-24 months
- Puppies typically double their birth weight in the first week
- Growth rate peaks between 3-5 months for most breeds
- Overweight puppies face serious skeletal development risks
- Regular weigh-ins at home and at the vet are essential for tracking
How Should You Understand Puppy Growth Patterns?
All puppies follow a similar growth curve shape, but the timeline and final size vary dramatically between breeds. A Chihuahua reaches adult weight at around 9 months, while a Great Dane may continue growing until 24 months. Understanding your puppy’s expected growth trajectory helps you ensure they are developing healthily.
Puppy growth is fastest in the first 6 months of life. During this period, most puppies will gain the majority of their adult weight. Growth then slows and continues more gradually until they reach their full adult size. The growth plates in a puppy’s bones close at different times depending on breed size, which is why large breed puppies should not do high-impact exercise until they are fully grown.
Weight is only one indicator of healthy growth. Your vet will also assess body condition, bone development, and overall proportions at each check-up.
What Is the Small Breed Growth Chart (Adult Weight Under 10kg)?
Small breeds like Chihuahuas, Yorkshire Terriers, Miniature Dachshunds, and Pomeranians have the fastest growth rate relative to their size. They typically reach adult weight between 9-12 months.
At 8 weeks, a small breed puppy typically weighs 0.5-2kg depending on the specific breed. By 3 months they have usually reached about 40% of their adult weight. By 6 months, they are approximately 75% of their adult weight. Most small breeds are at or very near their adult weight by 9-10 months.
Small breed puppies are particularly susceptible to hypoglycaemia (low blood sugar) during their rapid growth phase. Regular meals (4 times daily until 12 weeks, then 3 times daily) are essential to maintain stable energy levels.
What Is the Medium Breed Growth Chart (Adult Weight 10-25kg)?
Medium breeds like Cocker Spaniels, Border Collies, Beagles, and Staffordshire Bull Terriers typically reach adult weight between 12-14 months. Their growth is more moderate than small breeds but faster than large breeds.
At 8 weeks, a medium breed puppy typically weighs 3-6kg. By 3 months they have usually reached about 35% of their adult weight. By 6 months, approximately 65-70% of adult weight. By 12 months, most medium breeds are at or very near their adult weight, with some filling out slightly until 14 months.
Medium breeds have the most predictable growth patterns and fewer size-related health concerns during development. However, monitoring body condition is still important to prevent obesity.
What Is the Large and Giant Breed Growth Chart (Adult Weight Over 25kg)?
Large breeds (Labradors, German Shepherds, Golden Retrievers, 25-45kg adult weight) typically reach adult weight between 14-18 months. Giant breeds (Great Danes, Newfoundlands, Saint Bernards, over 45kg adult weight) may continue growing until 18-24 months.
At 8 weeks, a large breed puppy typically weighs 5-10kg. Giant breeds may weigh 8-15kg. By 3 months, large breeds have reached about 30% of their adult weight. By 6 months, approximately 60%. Growth continues steadily but more slowly from 6-18 months.
Large and giant breed puppies require special attention to nutrition. Too-rapid growth caused by overfeeding or inappropriate food can cause serious skeletal problems including hip dysplasia, elbow dysplasia, and osteochondrosis dissecans. Feed a large-breed-specific puppy food with controlled calcium levels and avoid excessive exercise on hard surfaces until growth plates close.
How to Weigh Your Puppy at Home?
Regular home weigh-ins help you track your puppy’s growth between vet visits. Weigh your puppy at the same time of day, ideally weekly for the first 6 months, then fortnightly until they reach adult weight.
For small puppies, use kitchen scales or baby scales. For larger puppies, weigh yourself on bathroom scales, then weigh yourself holding your puppy, and subtract the difference. Many UK pet shops and veterinary practices also have walk-on scales available for free use.
Record weights in a diary or spreadsheet and plot them against your breed’s expected growth curve. Consistent deviation from the expected range (above or below) warrants a discussion with your vet. Sudden weight loss or failure to gain weight can be early signs of health issues.
What Is the Puppy Weight Milestones by Breed Size?
| Age | Small Breed (% adult) | Medium Breed (% adult) | Large Breed (% adult) | Giant Breed (% adult) |
|---|---|---|---|---|
| 8 weeks | 25-30% | 20-25% | 15-20% | 10-15% |
| 3 months | 40-45% | 30-35% | 25-30% | 20-25% |
| 6 months | 70-80% | 60-70% | 55-60% | 45-50% |
| 9 months | 90-100% | 80-90% | 70-80% | 60-70% |
| 12 months | 100% | 95-100% | 85-90% | 75-80% |
| 18 months | 100% | 100% | 95-100% | 90-95% |
What Are the Common Mistakes to Avoid?
- Comparing your puppy’s weight to other breeds of different sizes
- Overfeeding large breed puppies to make them grow bigger faster
- Not accounting for neutering which can affect final size and weight
- Relying on online calculators that do not account for breed variation
- Ignoring body condition and focusing only on weight numbers
What To Do Next?
- Start a weight tracking diary or spreadsheet for your puppy
- Ask your vet for your breed’s specific growth curve at your next visit
- Read our Puppy Feeding Schedule by Age guide
- Read our Puppy Development Stages Guide
- Download our New Puppy Starter Checklist
What Are the Key Terms?
- Growth Plates
- Areas of developing cartilage at the ends of long bones where new bone growth occurs. They close (ossify) at maturity, ending growth. Injury to open growth plates can cause permanent skeletal deformity.
- Body Condition Score (BCS)
- A standardised 1-9 scale used by veterinarians to assess whether a dog is underweight, ideal, or overweight based on visual and physical assessment of fat coverage and body shape.
- Large Breed Puppy Food
- Specially formulated food with controlled calcium and energy levels designed to support steady, healthy growth in puppies that will exceed 25kg at adult weight.
- Hypoglycaemia
- Dangerously low blood sugar levels, particularly common in small breed puppies due to their high metabolic rate. Symptoms include weakness, trembling, and collapse.
- Growth Curve
- A graph showing expected weight at each age for a specific breed or breed size, used to track whether a puppy’s growth rate is within healthy parameters.
Frequently Asked Questions
How much weight should a puppy gain per week UK?
This varies hugely by breed. Small breed puppies typically gain 100-200g per week. Medium breeds gain 200-500g per week. Large breeds gain 500-900g per week during their peak growth phase (3-5 months). Giant breeds can gain over 1kg per week. Your vet can provide breed-specific guidance.
When do puppies stop growing UK?
Small breeds stop growing at 9-12 months, medium breeds at 12-14 months, large breeds at 14-18 months, and giant breeds at 18-24 months. Some dogs continue to fill out and add muscle after reaching their full height.
Is my puppy underweight?
If you can see your puppy’s ribs prominently, spine, or hip bones, they may be underweight. However, some breeds (like Whippets and Greyhounds) naturally appear leaner. Ask your vet to assess body condition score. For most puppies, ribs should be easily felt but not visible.
Does neutering affect puppy growth?
Yes. Neutering before growth plates close (typically before 12-18 months depending on breed) can result in slightly taller dogs as the growth plates remain open longer. It can also affect metabolism, making neutered dogs more prone to weight gain. Discuss timing with your vet.
How big will my mixed breed puppy get?
Predicting adult size for mixed breed puppies is less precise. A general rule is that a puppy at 14-16 weeks will be approximately half their adult weight. DNA testing can identify breed components and provide better size estimates. Your vet can also assess bone structure for size predictions.
What Are the Recommended Products?
These products are selected based on relevance to this guide. As an Amazon Associate, PetHub Online earns from qualifying purchases.
Digital Pet Scale
Accurate digital scales for tracking puppy weight at home, suitable for puppies up to 50kg
Large Breed Puppy Food
Controlled-calcium puppy food designed for breeds that will exceed 25kg at adult weight
Puppy Growth Record Book
Logbook for tracking weight, vaccination dates, and health milestones throughout puppyhood
Measuring Tape for Dogs
Flexible tape for measuring height, length, and chest circumference to track growth alongside weight
What Is the Get Our Free Puppy Care Checklist?
Download our comprehensive new puppy checklist covering everything from supplies to training milestones.
Sources & References
- Waltham Puppy Growth Charts
- Royal Veterinary College – Puppy Growth Study
- FEDIAF – Nutritional Guidelines for Growing Dogs
- The Kennel Club – Breed Size and Growth Information
- PDSA – Puppy Weight and Growth Guide
Trust & Transparency: PetHub Online provides research-backed pet care information for UK pet owners. Our content is based on published veterinary guidelines, manufacturer specifications, and publicly available expert guidance. We do not fabricate credentials, invent experts, or claim hands-on testing unless explicitly stated. Read our editorial policy.
Jason Parr & Sarah Parr
Founders, PetHub Online | Pet Product Research & Reviews
Jason and Sarah are UK-based pet owners and researchers dedicated to providing honest, well-researched pet care content. Every guide is based on veterinary guidelines, manufacturer data, and real owner experiences.
