20dwt是多少g？
20dwt = 31.1035g
是31.1035g，所以说成31g也没问题——四舍五入的误差在0.5%以内。
反过来，20g是多少dwt？
20g = 12.8603dwt
计算公式: g = dwt × 1.555174
该数值前后的 dwt → g
2 dwt3.1103g
4 dwt6.2207g
6 dwt9.331g
8 dwt12.4414g
10 dwt15.5517g
12 dwt18.6621g
14 dwt21.7724g
16 dwt24.8828g
18 dwt27.9931g
20 dwt31.1035g
22 dwt34.2138g
24 dwt37.3242g
26 dwt40.4345g
28 dwt43.5449g
30 dwt46.6552g
32 dwt49.7656g
34 dwt52.8759g
36 dwt55.9863g
38 dwt59.0966g
40 dwt62.207g