It depends on the drink. Water has no calories, while sodas have a few hundred calories, for example.
it is listed on their website:
http://www.mcdonalds.com/us/en/food/full_menu/beverages.html
310 calories.
about 180 calories
260 calories
250 calories
440 calories
190 calories without dressing in one serving of McDonalds chicken caeser salad.
One calories
There are 370 calories in a McDonald's McChicken.
290 calories
300
880
They have a 21-oz which is 210 calories.