20kcal是多少kJ？
20kcal = 83.68kJ
是83.68kJ，所以说成84kJ也没问题——四舍五入的误差在0.5%以内。
反过来，20kJ是多少kcal？
20kJ = 4.78kcal
计算公式: kJ = kcal × 4.184
该数值前后的 kcal → kJ
2 kcal8.37kJ
4 kcal16.74kJ
6 kcal25.1kJ
8 kcal33.47kJ
10 kcal41.84kJ
12 kcal50.21kJ
14 kcal58.58kJ
16 kcal66.94kJ
18 kcal75.31kJ
20 kcal83.68kJ
22 kcal92.05kJ
24 kcal100.42kJ
26 kcal108.78kJ
28 kcal117.15kJ
30 kcal125.52kJ
32 kcal133.89kJ
34 kcal142.26kJ
36 kcal150.62kJ
38 kcal158.99kJ
40 kcal167.36kJ