Convert from onca [Portuguese] to milligram

Unit Definition (onca [Portuguese])
The onça, once, oncia, onza is traditional names for the ounce unit in Romance languages. The Portuguese onça and Spanish onza equal 1/16 libra or about 28.69 grams (1.012 ounce).

Unit Definition (milligram)
The milligram is a very common metric unit of mass equal to 0.001 gram or 1000 micrograms (µg or mcg). One milligram equals approximately 0.015432 grain or 35.274 x 10E-6 ounce.