What is the Troy Weight Conversion Calculator?
The troy weight system is the standard for measuring precious metals such as gold, silver, platinum, and palladium. This calculator converts between the four common troy units — troy ounces (oz t), pennyweight (dwt), grains (gr) — and the metric gram (g). It is widely used by jewelers, bullion dealers, and investors. Note that a troy ounce (31.1035 g) is heavier than a standard avoirdupois ounce (28.3495 g), which is why precious-metal prices are quoted "per troy ounce."
How to use it
Enter the amount you want to convert and select the unit it is currently in. The calculator instantly shows the equivalent value in grams plus every other troy unit. For example, entering "1" with "Troy ounces" selected returns 31.1034768 grams, 20 pennyweight, and 480 grains.
The formula explained
The base conversion is $$\text{grams} = \text{troy ounces} \times 31.1034768$$. The other units derive from the troy ounce: one troy ounce holds exactly 20 pennyweight, so \(1\ \text{dwt} = 1.55517384\ \text{g}\). It also holds 480 grains, so \(1\ \text{gr} = 0.06479891\ \text{g}\). The calculator first converts your input to grams, then divides by each unit's gram value to produce all equivalents.
Worked example
Convert 10 pennyweight to grams: $$10 \times 1.55517384 = 15.5517384\ \text{g}.$$ That equals \(15.5517384 \div 31.1034768 = 0.5\) troy ounces, and \(15.5517384 \div 0.06479891 = 240\) grains.
FAQ
Is a troy ounce the same as a regular ounce? No. A troy ounce is about 31.10 g, while a standard (avoirdupois) ounce is about 28.35 g.
How many grains are in a troy ounce? Exactly 480 grains, and 24 grains make one pennyweight.
What metals use troy weight? Gold, silver, platinum, palladium, and other precious metals and gemstones are measured in troy units.
