The average mudslide alcoholic drink can have anywhere from 100 to 750 calories according to about.com. The calories in a mudslide can vary widely depending on size and ingredients.
A typical mudslide contains vodka, coffee liqueur, Irish cream and cream. A lower-calorie mudslide can be made by substituting coffee-flavored vodka for the coffee liqueur and vodka and substituting skim milk for cream. It is also possible to make a mudslide that is lower in calories by blending coffee-flavored vodka, skim milk, and coffee that has been cooled to room temperature with some ice. This blended version of the mudslide contains fewer calories and is still creamy and frothy, similar to a milkshake consistency.