How many calories in a cup of tea? A tea without milk or sugar is considered to have 0 calories. Milk can have 10-50 calories depending on its thickness. One teaspoon of sugar has 16 calories. If cream is added the calorie increases. A 100ml tea has an approximate calorie count of 10.8kcal. It has 1.5g carbohydrates, 1.2 proteins and 0.2 fat. If we are conscious about the thickness of milk and the amount of sugar added and avoid added cream to tea the calories get reduced.