We assume that carbohydrates and protein each have 4 kilocalories per gram, and that fat has 9 kilocalories per gram. Then the number of kilocalories in the peanut butter is ...
4(6 +9) +9(11) = 159 . . . . kilocalories
Each kilocalorie translates to 4.184 kilojoules, so the total is ...
(159 kCal)(4.184 kJ/kCal) = 665.256 kJ
2 Tbsp of crunchy peanut butter contains about 665 kJ of energy.
