It is a dessert with coffee under it, and the yolks are what make it one. Two egg yolks are 110 calories and 10g of fat, and the classic recipe uses 2 per cup. Khoeplus24h's breakdown for a standard cup is 2 yolks at 110, 25ml of condensed milk at 80, honey at 64 and 70ml of phin coffee at 1, which they round to 225. Most cafes use a little less sweetener than that, so 230 is a fair number for a 150ml cup in the Old Quarter.
It is small, which is the saving grace. A ca phe trung cup is 120 to 150ml, about half a ca phe sua da, and it is eaten with a spoon slowly because it is hot. Compared by the glass it is 230 against 130 for ca phe sua da, so nearly double, but almost nobody drinks 3 egg coffees a day. The foam has 7g of protein, which the condensed milk coffee does not.
The tourist versions are bigger. Cafes in the Old Quarter now sell egg coffee in 250ml glasses with double foam for 55,000 dong, which is about 400 calories. Ca phe trung da (iced) uses the same foam over more coffee at roughly the same 240. Cacao trung and matcha trung, the egg foam over chocolate or green tea milk, are 300 to 320 because the base is sweet milk instead of black coffee.