A pennyweight (dwt ) is a unit of mass equal to 24 grains, 1/20 of a troy ounce, 1/240 of a troy pound, approximately 0.054857 avoirdupois ounce and exactly 1.55517384 grams. It is abbreviated dwt, d standing for denarius an ancient Roman coin, later used as the symbol of an old British penny.
1 pennyweight = 24 grains = 1/20 Troy ounce = 1/240 Troy pound = 1.55517384 grams
- The pennyweight is the common weight used in the valuation and measurement of precious metals.
- Jewellers use the pennyweight in calculating the amount and cost of precious metals used in fabricating or casting jewellery.
- Dentists and dental labs still use the pennyweight as the measure of precious metals in dental crowns and inlays