Precious Metal Weight Calculator

A troy ounce (oz t) weighs 31.1035 grams, while a regular avoirdupois ounce (oz) weighs 28.3495 grams. This means a troy ounce is about 10% heavier than a regular ounce. The troy system is used exclusively for precious metals like gold, silver, platinum, and palladium worldwide. This distinction is crucial when buying or selling precious metals - if you confuse the two, you could lose approximately 10% of value. The troy system dates back to the Middle Ages and takes its name from Troyes, France, a major trading center.

One troy ounce of gold equals exactly 31.1034768 grams. This is the international standard used by markets, mints, and dealers worldwide. When gold prices are quoted per ounce (e.g., $2,000/oz), they always mean troy ounces. For reference: 1 troy oz = 31.1035g = 20 pennyweight (dwt) = 480 grains. A standard gold bar (Good Delivery bar) weighs 400 troy ounces (12.44 kg), while popular retail bars come in 1 oz, 10 oz, and 1 kg sizes.

Pennyweight (abbreviated dwt) is a unit of weight equal to 1/20 of a troy ounce or 1.55517 grams. It's primarily used in the jewelry industry in the United States and UK for weighing gold, silver, and gemstones. Jewelers prefer pennyweight because it provides a convenient middle ground between grams and troy ounces for small jewelry pieces. The name comes from the weight of a medieval English silver penny. When selling scrap gold to jewelers, they typically weigh in pennyweight and calculate value from there.

A tael is a traditional Asian unit of weight used primarily in Chinese-speaking regions for precious metals and traditional medicine. The most common standard is the Hong Kong tael, which equals 37.429 grams (1.2034 troy ounces). However, tael weights vary by region: Taiwan tael = 37.5g, Singapore tael = 37.7994g, and the Chinese market tael = 50g. Gold bars in Asia are often sold in tael units, and many Chinese gold jewelry shops price items per tael. When trading in Asian markets, always confirm which tael standard is being used.

A tola is a traditional unit of weight used primarily in India, Pakistan, Bangladesh, Nepal, and surrounding regions for gold and silver. One tola equals 11.6638 grams or approximately 0.375 troy ounces. The tola has historical roots as the weight of a silver rupee coin during British colonial rule. Today, gold bars and jewelry in South Asia are commonly sold in tola units. A standard "10 tola bar" (116.64g or 3.75 oz) is one of the most popular gold bar sizes in Indian markets. Wedding jewelry is often measured and quoted in tolas.

To calculate pure gold content, multiply the total weight by the purity percentage. For karat gold: 24K = 99.9% pure, 22K = 91.67%, 18K = 75%, 14K = 58.33%, 10K = 41.67%, 9K = 37.5%. Example: A 10-gram 18K gold necklace contains 10g × 0.75 = 7.5 grams of pure gold. The remaining 2.5g consists of alloy metals (copper, silver, zinc, nickel) that provide strength, durability, and color variations (rose gold, white gold). When selling gold, dealers pay based on pure gold content, not total weight.

.999 fine silver (also called "three nines fine" or "pure silver") contains 99.9% silver and 0.1% trace elements. This is the standard for silver bullion bars and coins like American Silver Eagles. .925 sterling silver contains 92.5% silver and 7.5% copper alloy, making it harder and more suitable for jewelry. Other standards include: .9999 (four nines fine) for premium bullion, .900 (coin silver) for pre-1965 US coins, and .800 (European silver) for antique pieces. When calculating scrap value, always account for actual silver content.

The grain is the smallest traditional unit in the troy weight system, equal to 0.0648 grams or 1/480 of a troy ounce. Despite being ancient (originally based on a grain of wheat or barley), it's still used today for: (1) Measuring very small quantities of gold in electronics and dental work, (2) Scientific precision in assaying and refining, (3) Pharmaceutical applications, (4) Ammunition and gunpowder measurement. While most modern transactions use grams or troy ounces, grains provide precision for tiny amounts where fractions of a gram matter.