How many calories in a mug of coffee with semiskimmed milk?

The calorie content of a cup of coffee is negligible if it is black.

With the milk, a cup of coffee is approximately 14 kcal so a mug would probably be about 18kcal. (semi-skimmed)

Mug of black coffee = 5kcal

Cup of coffee with semi-skimmed milk = 14 kcal

Sugar per teaspoon = 15kcal

These figures seem to be around average, some sites quote slightly higher or lower than these figures.

Hope this helps!