How Gold Is Weighed Around the World: Grams, Ounces, Tolas and Baht

Gold is traded globally, but not every market talks about its weight in the same way. International bullion markets usually quote gold in troy ounces, while retail buyers in many countries think in grams. South Asian markets often use the tola, and Thailand has its own traditional baht-weight system.

These units can make prices look very different even when the underlying value of the gold is the same. Understanding the conversions helps when comparing gold across countries, dealers, and product sizes.

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The most important rule: a gold ounce means a troy ounce

Precious metals are normally weighed in troy ounces, not the ordinary avoirdupois ounce used for many everyday goods.

1 troy ounce = 31.1034768 grams

The London Bullion Market Association states that the troy ounce is the traditional precious-metals unit and defines one troy ounce as exactly 31.1034768 grams.

This is important because a regular avoirdupois ounce is only about 28.35 grams. Using the everyday ounce when converting a gold price would produce the wrong result.

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Grams: the most practical retail unit

The gram is widely used for jewellery, small bullion bars and personal gold holdings. For many buyers, it is more intuitive than a troy ounce because gold products are commonly sold in weights such as 1 gram, 5 grams, 10 grams, 20 grams, 50 grams or 100 grams.

A kilogram of gold contains 1,000 grams, which is approximately 32.1507 troy ounces.

GoldRates uses gram-based pricing because it makes live gold rates easier to apply to jewellery and smaller physical-gold products.

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Troy ounces: the international market standard

The troy ounce remains the main weight unit for international spot gold, financial news and major wholesale-market quotations.

When a headline says gold is trading at a certain number of US dollars ‘per ounce’, it almost always means per troy ounce.

The troy system has been used for precious metals for centuries. Its continued use gives the global bullion market a common standard even when local buyers prefer other units.

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Tolas: widely recognised in South Asian gold markets

The tola is a traditional unit still recognised in parts of South Asia and the Middle East, especially in gold and jewellery markets.

According to the World Gold Council, one tola equals 0.374878 troy ounces. That is approximately 11.6638 grams.

1 tola ≈ 11.6638 grams

Because many buyers are more familiar with grams today, dealers and gold-price services often show both units.

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Baht: Thailand’s traditional gold-weight unit

Thailand uses the baht as both a currency name and a traditional gold-weight unit. When someone refers to a ‘baht of gold’, they are referring to weight, not the number of Thai baht being paid.

The Gold Traders Association of Thailand states that one baht-weight of gold bullion is 15.244 grams, while one baht-weight of gold jewellery is 15.16 grams.

1 baht of gold bullion = 15.244 grams

The slight difference between bullion and jewellery weight conventions is an important reminder that traditional market units can have local definitions. When comparing prices, always check exactly what form of gold and weight standard the dealer is using.

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Quick conversion table

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Why weight conversion matters for price comparison

A gold price is only meaningful when you know the unit behind it.

A dealer quoting 1,500 in a local currency per gram cannot be compared directly with a market price quoted per troy ounce or per tola. The units first need to be converted onto the same basis.

The same rule applies when comparing prices between countries. Before deciding that gold is cheaper in one market, make sure you are comparing:

• The same weight unit
• The same currency or a properly converted currency value
• The same purity
• The same type of product, such as bullion versus jewellery
• The same time or market session where possible

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A simple ounce-to-gram example

Suppose gold is quoted at US$4,000 per troy ounce. To estimate the 24K value per gram:

US$4,000 ÷ 31.1034768 ≈ US$128.60 per gram

That conversion changes only the weight unit. If you also want the price in another currency, an exchange-rate conversion is required.

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A simple tola conversion

If the 24K gold price is US$128.60 per gram, the theoretical underlying value of one tola is:

US$128.60 × 11.6638 ≈ US$1,499.9 per tola

The figure is illustrative and does not include premiums, taxes, making charges, or other retail costs.

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Weight and purity are separate

A weight tells you how heavy the item is. It does not tell you how much pure gold it contains.

A 20-gram 18K bracelet and a 20-gram 24K bar have the same gross weight, but very different pure-gold content. The 18K bracelet is 75% gold by fineness, while 24K investment gold is usually near pure.

For that calculation, see How to Calculate the Pure-Gold Content of Jewellery on GoldRates.

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Traditional units can vary by market

Not every traditional gold unit is universal. Units such as the tael, baht, and other regional measures can have definitions tied to local market practice.

That is why grams and troy ounces are useful as common comparison standards. When in doubt, convert a local unit into grams before comparing the price with another market.

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The key takeaway

Gold is measured in different units around the world, but the metal itself does not change. The troy ounce is the main international bullion standard, grams are widely used for retail buying, the tola remains important in South Asian markets, and Thailand uses its own baht-weight convention.

The safest way to compare prices is to convert every quote into the same weight, currency, and purity basis. Once those three factors match, prices from very different markets become much easier to understand.