With added sugar, rich coconut and sweetened, condensed milk, Thai iced tea can be very high in calories. In fact, this cool, creamy indulgence usually contains more calories than the average soda. If you're making Thai iced tea at home, you can reduce the calorie load by using light coconut milk and only a small amount of sugar.
The exact number of calories in your Thai iced tea depends on the preparation, but one recipe from the Epicurious website contains just over 300 calories per cup. Not all versions are that rich, however: MyFitnessPal estimates the average Thai iced tea to have about 180 calories per cup. Most of the calorie content comes from coconut milk and/or sweetened condensed milk -- different recipes may use one or both of these ingredients. Light coconut milk, however, may contain only about 45 calories per cup. Therefore, Thai iced tea made with black tea, a serving of light coconut milk and 1 teaspoon of sugar would have about 60 calories.