Here's how to calculate the total kilocalories in Jane's breakfast:

* Carbohydrates: 85 grams * 4 calories/gram = 340 calories

* Protein: 20 grams * 4 calories/gram = 80 calories

* Fat: 18 grams * 9 calories/gram = 162 calories

Total Calories: 340 + 80 + 162 = 582 kilocalories

Therefore, Jane consumed 582 kilocalories at breakfast.