Gold Weight Converter (troy ounce, 돈, 냥, carat, gram)

Understanding the gold weight converter — concept and principle

This converter changes a precious-metal weight between troy ounces, grams, the Korean units don (돈) and nyang (냥), metric carats, tola, kilograms and ordinary avoirdupois ounces. Use it to compare an international gold or silver price quoted per troy ounce with a Korean shop price per don, or to check the weight of a bar, coin or piece of jewellery.

How it is calculated

Every unit is converted to a base unit and then to the target unit:

result = value × (size of the "from" unit) ÷ (size of the "to" unit)

• 1 troy ounce (ozt) = 31.1034768 g exactly.
• 1 don = 3.75 g; 1 nyang = 10 don = 37.5 g.
• 1 metric carat (ct) = 0.2 g exactly.
• 1 tola = 180 grains = 11.6638038 g.
• 1 avoirdupois ounce = 28.349523125 g.

The principle

All these units are defined as fixed amounts of mass, so converting is simple multiplication. The troy system is built on the grain (64.79891 mg): a troy ounce is 480 grains, while an ordinary avoirdupois ounce is 437.5 grains. That is why a troy ounce is about 9.7% heavier. The tola is 180 grains, exactly 3/8 of a troy ounce. The don and nyang are traditional East Asian units that the Korean gold trade still uses, fixed at 3.75 g per don.

Worked example

Default inputs: 1 troy ounce to grams.

1. 1 ozt = 31.1034768 g.
2. In don: 31.1034768 ÷ 3.75 = 8.29426048 don, or 0.829426048 nyang.
3. In carats: 31.1034768 ÷ 0.2 = 155.517384 ct.
4. In tola: 480 ÷ 180 = 2.666666667 tola; in ordinary ounces: 480 ÷ 437.5 = 1.097142857 oz.

How to read the result

To turn an international price per troy ounce into a price per don, divide it by 8.29426 (and convert the currency). Remember that a weight converter gives only the mass of metal. The price you pay for jewellery also reflects purity, workmanship, taxes and the dealer's margin. Purity is shown in karats or fineness: 24K is pure gold, 18K is 18/24 = 75% gold, and 14K is about 58.3% gold (often stamped 585).

Common mistakes

• Using an ordinary ounce (28.35 g) for a gold price quoted per troy ounce.
• Confusing carat (ct, a weight of 0.2 g for gemstones) with karat (K, gold purity).
• Treating the weight of a 14K or 18K item as the weight of pure gold.
• Mixing up don and nyang; 1 nyang is 10 don.

Frequently asked questions

How many grams is 1 don of gold?

3.75 g.

How many don are in a troy ounce?

About 8.294 don.

How much pure gold is in 1 don of 18K gold?

3.75 g × 0.75 = about 2.81 g.

Is a troy ounce heavier than a regular ounce?

Yes. A troy ounce is 31.10 g and an avoirdupois ounce is 28.35 g.

Sources: NIST Handbook 44, Appendix C (troy and avoirdupois units) · NIST Special Publication 811 (2008), Appendix B