There are 12 dishes ranked on this page. The lightest is Liu Sha Bao at 190 kcal per 1 bun, the heaviest is Lo Mai Kai at 380 kcal per 1 bowl, and the average lands around 276 calories a serving. 7 of them come in under 300 calories.
The spread here is narrower than most categories, about 190 calories between the lightest and the heaviest. That means portion size and what you order alongside it matter more than which dish you pick.