European robins measure from 12 to 14.5 centimeters in body length, with a height of body from 12 to 3.6 meters and a wingspan of 21 centimeters; the species' mass ranges from 15.1 to 18.2 grams. The embryo stage has a body length from 1.9 to 2.1 centimeters and a body mass from 1.8 to 2.2 grams, while the nestling stage exhibits a body mass from 3 to 16 grams and a body length from 5 to 10 centimeters. During the rapid growth phase, the young have a body mass from 14 to 20 grams and a body length from 12 to 14 centimeters. Adult European robins weigh from 15 to 23 grams and have a body length from 12.5 to 14.5 centimeters.