Convert from carat [international] to qintar [Arab]

Unit Definition (carat [international])
The carat [international] is a unit of mass used for diamonds and other precious stones. Originally spelled karat, the word comes from the Greek keration, a carob bean; carob beans were used as standards of weight and length in ancient Greece in much the same way barleycorns were used in old England. Traditionally the carat was equal to 4 grains. The definition of the grain differed from one country to another, but typically it was about 50 milligrams and thus the carat was about 200 milligrams.

Unit Definition (qintar [Arab])
The qintar is a traditional Arabic unit of weight, often called the cantar in English. The qintar is the Arabic counterpart of the European quintal. The unit varied in size from market to market and over time. In recent years, the qintar has been interpreted as an informal metric unit equal to 50 kilograms (110.23 pounds); traditional qintars tended to be a few percent larger than this. The qintar is equal to 100 rotls.