A pennyweight (dwt) is simply a division of an ounce-- a "troy"
ounce which is an ounce used to measure precious metals. There are 20
dwts in each troy oz.
While ounces differ-- troy, standard (or Avoirdupois) --grams are
There are 28.3 (approx.) grams in an Avoirdupois oz. while a Troy
ounce contains 31.1 grams and so is heavier.
A Troy ounce is usually divided into either 20 dwts or 31.1 grams.
One dwt equals 1.55 grams.
What people choose to measure in, either grams or pennyweights, is
really a matter of choice. I most often measure in pennyweights and
covert to grams if I need to. I like being able to divide by 20. My
scales can toggle between grams and pennyweights.
Take care, Andy