West Highland White Terrier Weight Chart by Age

An adult West Highland White Terrier weighs 15.0–20.0 lb (6.8–9.1 kg), according to the American Kennel Club breed standard, which gives one range for both sexes.

At 3 months a typical male weighs 7.8 lb (3.5 kg) and a typical female 7.6 lb (3.4 kg). Half of males weigh 5.6–10.5 lb (2.5–4.8 kg), and half of females 5.9–9.6 lb (2.7–4.4 kg). A typical puppy is around 39% of its adult weight at this age.

At 4 months a typical male weighs 10.6 lb (4.8 kg) and a typical female 10.2 lb (4.6 kg). Half of males weigh 7.8–14.1 lb (3.5–6.4 kg), and half of females 7.9–12.9 lb (3.6–5.8 kg). A typical puppy is about 53% of the way to adult weight.

At 6 months a typical male weighs 14.9 lb (6.8 kg) and a typical female 13.8 lb (6.3 kg). Half of males weigh 11.0–19.7 lb (5.0–8.9 kg), and half of females 10.9–17.4 lb (4.9–7.9 kg).

At 12 months a typical male weighs 18.4 lb (8.3 kg) and a typical female 17.1 lb (7.8 kg). Half of males weigh 13.5–24.4 lb (6.1–11.0 kg), and half of females 13.3–21.8 lb (6.0–9.9 kg). That is about 92% of final weight, with the rest filling in over the following months.

Dogs of this size that were weighed both as puppies and as adults ended up at about 1.9 times their 4-month weight, in records from US veterinary clinics. The calculator on the home page uses those records for the puppy’s own age and weight, and returns a range rather than one number.

Height is usually settled first; weight keeps filling in for longer. On the growth curve for its size, a West Highland White Terrier stays above 95% of adult weight from about 14 months, and the last 8% after its first birthday comes on slowly.

The American Kennel Club gives one range for both sexes, 15 to 20 lb, so the male and female charts above share one adult range. Measured UK Westies do differ: adult males averaged 10.1 kg and females 9.0 kg (O’Neill et al. 2019), so expect a grown male to sit a little higher.

A small breed, defined by adult weight. That classification determines the growth curve used here: veterinary research shows dogs of similar adult size grow at similar rates regardless of breed.

Not necessarily: 1 in 10 healthy puppies weighs less than the lightest figure in the table. What matters more is the trend. A puppy that drifts from one part of the range to a lower one is worth checking: look at its body condition and ask your vet about its diet. A single low reading is not a diagnosis.

Body condition tells you more than the scale. You should be able to feel the ribs under a thin layer of fat without pressing, see a waist from above, and see the belly tuck up from the side. A dog can sit inside the weight range and still carry too much fat.

Most published charts come from one breeder’s litters or from unsourced rules of thumb, and many do not say whether the figures are for males, females or both. The ranges here come from centile curves fitted to millions of veterinary bodyweight records, scaled to the AKC adult range, and split by sex.

The research behind these curves found neutering shifted growth trajectory only slightly, by less than the variation between individual dogs, so separate curves were not needed. Neutering is associated with a higher chance of becoming overweight in adulthood, which is a body condition question rather than a growth chart one.

An adult West Highland White Terrier weighs 6.8–9.1 kg for both sexes under the American Kennel Club standard. A typical male weighs 3.5 kg at 3 months, 6.8 kg at 6 months and 8.3 kg at 12 months; a typical female 3.4 kg, 6.3 kg and 7.8 kg. The charts above give every month in kilograms, with a switch to pounds.

The American Kennel Club standard gives one range for both sexes, 15.0–20.0 lb (6.8–9.1 kg); it does not publish a separate female figure. A typical female West Highland White Terrier weighs 10.2 lb at 4 months, 13.8 lb at 6 months and 17.1 lb at 12 months. Weight stays above 95% of the adult figure from about 14 months. The female chart above gives every month.

The American Kennel Club standard gives one range for both sexes, 15.0–20.0 lb (6.8–9.1 kg); it does not publish a separate male figure. A typical male West Highland White Terrier weighs 10.6 lb at 4 months, 14.9 lb at 6 months and 18.4 lb at 12 months. Weight stays above 95% of the adult figure from about 14 months. The male chart above gives every month.