Gold Weight Units Explained: Grams, Troy Ounces, Tola, Tael and Baht
Why gold has its own units
Precious metals were traded long before the metric system existed, and each trading region developed its own weights. Many of those units survived because buyers and sellers trust them, banks quote them and families have measured their savings in them for generations. The result is that the same gram of gold can be described as 0.032 troy ounces, 0.086 tola, 0.027 tael or 0.066 baht, depending on where you are standing.
The good news is that every traditional unit has a fixed weight in grams. Once you know that number, converting a price is simple arithmetic, and our gold unit converter does it for you instantly.
The troy ounce: the world benchmark
Every international gold price — the LBMA benchmark in London, COMEX futures in New York, the spot price on this site — is quoted in US dollars per troy ounce. One troy ounce weighs exactly 31.1034768 grams. The ounce used for food in the United States (the avoirdupois ounce) weighs 28.3495 grams, so a troy ounce is roughly 9.7% heavier. Confusing the two is the most common mistake people make when they weigh jewelry at home and multiply by the spot price.
The troy system has two smaller units that are still used in the jewelry trade, especially in the United States and the United Kingdom:
- Pennyweight (dwt): one twentieth of a troy ounce, or 1.5552 grams. Some scrap buyers quote prices per pennyweight, which makes their offer look larger than a per-gram price.
- Grain: 0.0648 grams. There are 24 grains in a pennyweight and 480 grains in a troy ounce. It appears mainly in technical specifications and in the definition of the tola.
The troy pound (12 troy ounces, 373.24 grams) is now almost never used for gold.
The gram and the kilogram
Outside North America and the UK bullion market, the gram is the normal retail unit. Jewelers in Europe, Latin America, the Middle East and most of Asia quote prices per gram, usually for the local jewelry karat: 18K in Spain or Colombia, 21K in Saudi Arabia, 22K in India. Large investment bars are sold by the kilogram: a kilo bar weighs 1,000 grams or 32.15 troy ounces and is the standard size for institutions and wealthy private buyers.
Traditional units by region
The table below shows the weight of each unit and what that weight of pure 24K gold is worth today at the live spot price.
| Unit | Weight | 24K value now | Where it is used |
|---|---|---|---|
| Gram | 1 g | 130.65 USD | Worldwide retail |
| Troy ounce | 31.1035 g | 4,063.60 USD | International price benchmark |
| Tola | 11.6638 g | 1,523.85 USD | India, Pakistan, Nepal, Bangladesh, the Gulf |
| Tael (Hong Kong) | 37.429 g | 4,890.02 USD | Hong Kong, Macau |
| Baht | 15.244 g | 1,991.59 USD | Thailand |
| Chỉ | 3.75 g | 489.93 USD | Vietnam |
| Don | 3.75 g | 489.93 USD | South Korea |
| Sovereign / pavan | 8 g | 1,045.18 USD | South India, Sri Lanka |
| Mithqal (Islamic) | 4.25 g | 555.25 USD | Zakat calculations |
| Pennyweight | 1.5552 g | 203.18 USD | US and UK jewelry trade |
| Kilogram | 1,000 g | 130,648 USD | Large bars |
- Tola (11.6638 g): defined as 180 grains. India adopted the metric system decades ago, but the tola is still the everyday unit in Pakistan, Nepal and Bangladesh (where it is also called the bhori or vori) and in Gulf souks. Ten-tola bars, weighing 116.64 grams, are popular savings bars.
- Tael: careful — there are several. Hong Kong’s gold tael is 37.429 g, Taiwan’s is 37.5 g and the Singapore and Malaysia tahil is 37.8 g, while mainland China now uses a metric liang of 50 g. Always ask which tael a price refers to.
- Baht (15.244 g): Thai gold bars of 96.5% purity are priced per baht-weight of 15.244 g; jewelry uses a slightly lighter baht of 15.16 g. Thai prices are therefore for 23K gold, not 24K.
- Chỉ and lượng: in Vietnam one lượng (tael) weighs 37.5 g and one chỉ is a tenth of that, 3.75 g. The Korean don is also 3.75 g.
- Sovereign or pavan (8 g): in Tamil Nadu, Kerala and Sri Lanka jewelry is weighed in sovereigns of 8 grams. The British gold sovereign coin, by contrast, weighs 7.99 g and contains 7.32 g of pure gold.
- Mithqal: the Islamic mithqal of about 4.25 g is the basis of the zakat threshold (20 mithqal = 85 g). Market mithqals differ: Iranian dealers use a mesghal of about 4.608 g and Iraqi markets a mithqal of 5 g.
How to convert a gold price between units
Every conversion follows the same two steps: turn the price into a price per gram, then multiply by the grams in the unit you want.
Price per new unit = price per old unit ÷ grams in old unit × grams in new unit
For example, if 24K gold costs 4,063.60 USD per troy ounce, one gram is worth that amount divided by 31.1035, which is 130.65 USD. One tola is then 11.6638 times the gram price: 1,523.85 USD.
Purity is a separate step. If you are converting the price of 22K gold, multiply the pure-gold price by 0.916; for 18K, by 0.750. Our guide to karats lists every purity factor.
Common mistakes to avoid
- Using a kitchen scale in ounces. Weigh in grams and convert; a household ounce is not a troy ounce.
- Comparing different purities. A Thai baht price is for 96.5% gold and a Dubai gram price is often quoted for 22K. Convert both to pure gold before comparing.
- Mixing up pennyweights and grams. A buyer offering "40 per dwt" is paying about 25.7 per gram, not 40.
- Assuming every tael is the same. The difference between a 37.429 g tael and a 50 g liang is more than 30%.
When in doubt, ask for the price per gram and the purity in writing. Those two numbers are enough to check any quote against the live gold price.