Pennyweight Calculator
& Conversion Chart

Pennyweight is a standard unit of measurement used in the precious metals industry. It originated as a unit of the troy weight system in 15th Century England and remains the standard for valuing precious metals today.

During 15th Century England, the weight of an English penny was exactly 1/20th of a troy ounce and 1/240th of a troy pound of sterling silver. Therefore, there are 20 pennyweights in a troy ounce and 12 troy ounces in a troy pound.

Although the same grain is used in both the troy weight system and the more common avoirdupois system (used in the United States), a troy ounce is heavier than an avoirdupois ounce, and a troy pound is lighter than an avoirdupois pound. There are 20 pennyweights in a troy ounce, compared to 31.1 grams in a troy ounce.

With prices set per troy ounce by the London fix, calculating a pennyweight price on the spot can be tricky. To help, we’ve provided our pennyweight calculator and conversion chart below. Use these tools to help determine the value of your precious metals.