about the same number of calories, (224 calories in a donut, 207 in a bagel) but those calories come from sugar and fat in the donut (4 times the sugar and 12 times the amount of fat).
That's a rather small bagel (75g). The issue here is mass. Bagels are much denser than donuts. Calorie Count has 285 calories in a medium, plain toasted bagel (100g) and 239 calories in a 60g medium glaze yeast donut.
Sources:
http://www.wolframalpha.com/input/?i=calories+in+a+donut http://www.wolframalpha.com/input/?i=calories+in+a+bagel