Gold Weight Units Explained — Ounce, Gram, Tael, Tola, Lượng & More
Gold is bought, sold, and quoted in different weight units depending on where you are in the world. Understanding these units — and how to convert between them — is essential whether you're checking spot prices, buying jewelry, or investing in bullion.
The Troy Ounce — The Global Standard
The troy ounce (oz t) is the international standard for pricing gold. When you see "$4,500/oz" on any financial platform, it refers to one troy ounce.
- Weight: 31.1035 grams
- Not the same as a regular (avoirdupois) ounce, which is only 28.35 grams
- Used by: All major exchanges (COMEX, LBMA, Shanghai Gold Exchange)
A troy ounce is about 10% heavier than a kitchen ounce. This distinction matters when calculating gold value.
Gram and Kilogram
The metric system units are universally understood and commonly used in Europe, jewelry retail, and industrial applications.
| Unit | Weight | Relation to 1 Troy Ounce |
|---|---|---|
| Gram | 1 g | 1 oz = 31.1035 g |
| Kilogram | 1,000 g | 1 oz = 0.0311035 kg |
Price Conversion
- Price per gram = Price per oz ÷ 31.1035
- Price per kilogram = Price per oz × 32.1507
Lượng (Cây) — Vietnam
Vietnamese Gold Unit
Weight
37.5 g
Units per Oz
0.82943
Price Multiplier
1.20565
The lượng (also called cây vàng) is Vietnam's traditional gold unit. Since 1 lượng is heavier than 1 troy ounce, gold priced per lượng is always more expensive than per ounce. Subdivided into chỉ (1 lượng = 10 chỉ = 3.75g each) and phân (1 chỉ = 10 phân).
Tael — Hong Kong & Taiwan
Hong Kong / Taiwan Gold Unit
Weight
37.429 g
Units per Oz
0.83099
Price Multiplier
1.20337
The tael (兩) is the traditional Chinese weight unit used in Hong Kong and Taiwan gold markets. The Hong Kong tael is slightly lighter than the Vietnamese lượng (37.429g vs 37.5g).
Tael — Mainland China
Mainland China Gold Unit
Weight
50.0 g
Units per Oz
0.62207
Price Multiplier
1.60754
China uses a different tael standard (市两) that is significantly heavier. This makes the Chinese tael the most expensive per-unit gold price among all common units.
Baht — Thailand
Thai Gold Unit
Weight
15.244 g
Units per Oz
2.04036
Price Multiplier
0.49011
The baht is Thailand's traditional gold weight unit (not to be confused with the Thai currency). Thai gold is commonly sold in 96.5% purity (23.16 karat), which differs from the 99.99% standard used internationally.
Tola — India, Pakistan & Bangladesh
South Asian Gold Unit
Weight
11.6638 g
Units per Oz
2.6667
Price Multiplier
0.375
The tola (also spelled "tolah") is the traditional gold weight unit across South Asia. India is the world's second-largest gold consumer — jewelry purchases, wedding gold, and investment gold are all commonly measured in tolas.
Don — South Korea
Korean Gold Unit
Weight
3.75 g
Units per Oz
8.29453
Price Multiplier
0.12056
The don (돈) is Korea's traditional gold weight unit, still used in local gold shops and jewelry stores.
Complete Conversion Table
| Unit | Region | Weight (g) | Units per Oz | Price Multiplier |
|---|---|---|---|---|
| Troy Ounce | Global | 31.1035 | 1.0 | 1.0 |
| Gram | Global | 1.0 | 31.1035 | 0.03215 |
| Kilogram | Global | 1,000 | 0.0311035 | 32.1507 |
| Lượng | Vietnam | 37.5 | 0.82943 | 1.20565 |
| Tael (HK) | Hong Kong | 37.429 | 0.83099 | 1.20337 |
| Tael (CN) | China | 50.0 | 0.62207 | 1.60754 |
| Baht | Thailand | 15.244 | 2.04036 | 0.49011 |
| Tola | India | 11.6638 | 2.6667 | 0.375 |
| Don | Korea | 3.75 | 8.29453 | 0.12056 |
Price Multiplier = how to convert from $/oz: multiply the ounce price by this factor to get the price in that unit.
How to Convert Between Units
To convert any gold price between two units:
Convert the price to per troy ounce first (divide by the source unit's multiplier)
Then multiply by the target unit's multiplier
Or use our Gold Calculator for instant conversions between all units.
Why Different Units Exist
Gold weight standards evolved independently across civilizations over thousands of years. The troy ounce comes from medieval France (Troyes), the tael from Imperial China, the tola from the Mughal Empire, and the baht from the Sukhothai Kingdom. Despite globalization standardizing financial markets around the troy ounce, local units persist because they're deeply embedded in cultural practices — especially around weddings, festivals, and inheritance.