Convert from once [France] to pennyweight [troy]

Unit Definition (once [France])
The onça, once, oncia, onza is traditional names for the ounce unit in Romance languages. The French once equals 1/16 livre or about 30.59 grams (1.079 ounce).

Unit Definition (pennyweight [troy])
The pennyweight is a unit of weight in the traditional troy system, equal to 24 grains or 1/20 troy ounce. One pennyweight is approximately 1.5552 gram.