How big does a Sussex Spaniel get?

A full-grown Sussex Spaniel is a medium dog, weighing about 51 lb as an adult.

Adult weight: 51 lb
Also in kilograms: 23 kg
Size class: Medium

As a medium breed, a Sussex Spaniel reaches its adult weight earlier than a large dog — smaller breeds finish growing sooner (Hawthorne et al., 2004).

Compare every breed’s adult weight·Your dog’s age in human years

Weight varies within the Sussex Spaniel by sex, genetics and health, and mixed-breed dogs fall between their parents. This is a typical range, not a guarantee.

Verified on July 22, 2026. Based on Wikidata — dog breed mass (property P2067) (Wikimedia Foundation, requête du 2026-07-22, licence CC0) and Body-Weight Changes during Growth in Puppies of Different Breeds (Hawthorne et al., Journal of Nutrition, 2004, vol. 134, p. 2027S). See the method.