4.184 × 106 J – energy released by explosion of onekilogram of TNT
106 J = 239 kcal – the nutritional value of a snack (e.g. a Mars bar) is around that value, typical servings of staple food such as 150 g of rice or 200 g of wheatbread as well.
1500 kcal = 6.3× 106 is an often recommended value for the nurtional energy a woman not doing heavy labour needs per day (2000 kcal = 8.4× 106 for men).