The egg is the smallest part. A quail egg is about 9g and 14 calories, which is nothing. Then it gets a thick coat of flour and cornstarch batter, about 10g dry per egg, and goes into oil that has been reused since morning. The batter soaks up 3 to 4g of oil per piece. That turns a 14 calorie egg into a 65 calorie ball. Kawaling Pinoy's recipe card comes out at 275 for 3 pieces, but it counts the whole pot of frying oil across the batch, which overstates it.
The sauce is sugar. The sweet kwek-kwek sauce is vinegar, brown sugar, cornstarch and chili, and a good ladle over 4 pieces is about 30 calories. The spicy vinegar version (sukang maanghang) is closer to 5. Most vendors let you choose, and the spicy vinegar is the one to pick if you are counting.
At 5 pesos a piece it is easy to eat 8 or 10 while waiting for a jeep. Ten pieces is 650 calories, which is a full meal from something that felt like a snack. The tokneneng version made with a chicken egg is bigger, about 150 calories each, because the batter shell is thicker and there is more egg.