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
The lượng (also called cây vàng) is Vietnam's traditional gold unit and remains the standard for domestic gold pricing, especially for SJC gold bars.
- Weight: 37.5 grams (exactly)
- 1 troy ounce = 0.82943 lượng
- Price per lượng = Price per oz × 1.20565
Since 1 lượng is heavier than 1 troy ounce, gold priced per lượng is always more expensive than per ounce.
The lượng is subdivided into chỉ (1 lượng = 10 chỉ = 3.75g each) and phân (1 chỉ = 10 phân).
Tael — Hong Kong & Taiwan
The tael (兩, also romanized as "liang") is the traditional Chinese weight unit used in Hong Kong and Taiwan gold markets.
- Weight: 37.429 grams (Hong Kong tael)
- 1 troy ounce = 0.83099 tael
- Price per tael = Price per oz × 1.20337
The Hong Kong tael is slightly lighter than the Vietnamese lượng (37.429g vs 37.5g), resulting in a marginally lower price per unit.
Tael — Mainland China
China uses a different tael standard (市两) that is significantly heavier.
- Weight: 50.0 grams
- 1 troy ounce = 0.62207 tael (CN)
- Price per tael (CN) = Price per oz × 1.60754
This makes the Chinese tael the most expensive per-unit gold price among all common units.
Baht — Thailand
The baht is Thailand's traditional gold weight unit (not to be confused with the Thai currency).
- Weight: 15.244 grams
- 1 troy ounce = 2.04036 baht
- Price per baht = Price per oz × 0.49011
Thai gold is commonly sold in 96.5% purity (23.16 karat), which differs from the 99.99% purity standard used internationally.
Tola — India, Pakistan & Bangladesh
The tola (also spelled "tolah") is the traditional gold weight unit across South Asia, widely used in India's massive gold jewelry market.
- Weight: 11.6638 grams
- 1 troy ounce = 2.6667 tola
- Price per tola = Price per oz × 0.375
India is the world's second-largest gold consumer. Gold jewelry purchases, wedding gold, and investment gold are all commonly measured in tolas.
Don — South Korea
The don (돈) is Korea's traditional gold weight unit, still used in local gold shops and jewelry stores.
- Weight: 3.75 grams
- 1 troy ounce = 8.29453 don
- Price per don = Price per oz × 0.12056
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.