It measures in length. Weight across the subspecies can range from . For comparison, the blue whistling thrush commonly weighs twice as much as an American robin. This species is possibly the largest extant thrush though size overlap does occur with the similar by length great thrush and the insular Amami thrush, whose mean body mass falls around the middle of those of the whistling thrush. Among standard measurements, the wing chord can measure long, the tarsus is and the bill is . Size varies across the range with larger thrushes found to the north of the species range and slightly smaller ones to the south, corresponding with Bergmann's rule. In northern China, males and females average and , whereas in India they average and .