Dog Size Calculator
Weigh your puppy, note its age in weeks and choose the expected breed size. The calculator estimates the adult weight range, how much it has grown so far and when it will stop growing.
- Adult weight estimate
- Growth by breed size
- Time to full size
A guide for healthy puppies on a normal diet. Your vet is the best judge of healthy growth.
Puppies grow at very different speeds. A Chihuahua reaches half its adult weight at about 7 weeks. A Great Dane takes about 17 weeks to get there and keeps growing until around two years old. The breed size you pick sets the growth curve the estimate follows.
Dog size classes
Adult weights and growth times by size. Search for a breed or weight.
| Class | Adult weight (kg) | Example breeds | Fully grown |
|---|---|---|---|
| Toy | Under 5 | Chihuahua, Yorkshire Terrier | 9 to 10 months |
| Small | 5 to 10 | Jack Russell, Shih Tzu | 10 to 12 months |
| Medium | 10 to 25 | Cocker Spaniel, Border Collie | 12 to 15 months |
| Large | 25 to 45 | Labrador, German Shepherd | 15 to 18 months |
| Giant | Over 45 | Great Dane, Mastiff | 18 to 24 months |
Mixed breeds often fall between two classes. If you know the parents' weights, the average of the two is a good guide to choose the class.
How fast each size grows
Share of adult weight by age. Slide the age in weeks.
By 20 weeks a toy breed is almost fully grown, while a giant breed is barely more than half its adult weight. Feeding large breed puppy food slows growth to protect their joints.
How to weigh a puppy at home
Bathroom scales work fine. Follow these steps.
Weigh yourself
Stand on the scales and note the reading.
Weigh at the same time of day, before a meal, every two weeks. Plotting the numbers makes it easy to spot if growth stalls or speeds up.
Growth by size class
Small and giant breeds grow very differently. Pick a size to compare.
Grows fast and finishes early. Most of the weight is gained in the first six months.
Steady growth with most of the size reached by 9 months.
Grows for well over a year and needs controlled feeding.
The slowest to mature, still filling out at two years.
Large and giant puppies should not do long runs or lots of jumping until their growth plates close, usually after 12 to 18 months.
Planning for an adult dog
Buy for the dog it will become. Tick these off.
Tick each item as you go.
Crates should let the adult dog stand, turn and lie flat. Buy one for the adult size and use a divider while the puppy is small.
What the estimate shows
Growth so far and still to come. Each tile explains one result.
A likely range in kilograms.
Share of adult weight reached.
Toy to giant, from the estimate.
Typical age for the size class.
Kilograms still to come.
Weigh again every few weeks and rerun the calculator. The estimate tightens as the puppy gets older and closer to adult size.
Frequently Asked Questions
No question matches that search.
How can I tell how big my puppy will get?
Weigh it, note the age in weeks and use a growth curve for the breed size. Paw size and the parents' weights are useful checks.
At what age is a dog half its adult weight?
Around 8 weeks for small breeds, 10 for medium, 13 for large and 17 for giant breeds.
When do dogs stop growing?
Small breeds at about 10 to 12 months, large breeds at 15 to 18 months and giant breeds as late as two years.
Do big paws mean a big dog?
Often, but not always. Paws are a rough guide. Weight and age give a better estimate.
How accurate is a puppy weight calculator?
Usually within 10% for purebred dogs from about 12 weeks. Mixed breeds vary more.
How big will a 12 week old Labrador get?
A 12 week Lab weighing 10 kg usually reaches 28 to 34 kg as an adult.
Can I double my puppy's weight at 16 weeks?
That rule works for some medium breeds. It underestimates large and giant breeds, which are less grown at 16 weeks.
Plan for the dog your puppy will become
Weigh regularly, choose the right breed size and use the estimate to buy the right crate, bed and food. Check with your vet at each visit, and enjoy watching your puppy grow.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.