Gold bar sizes and weights

Gold bars are sold by weight, but two weight systems are in use at once: metric grams and kilos, and troy ounces. That is why a dealer's list jumps from 20 g to 1 oz to 50 g. This guide sets out every common size with both measures, the dimensions refiners publish, what each size is worth at today's spot price, how the cost per gram changes as bars get bigger, and how the four main English-speaking markets tax them.

What gold bar sizes are there, and what does each weigh?

All the sizes below are fine gold weights for bars of 99.99% purity (also written 999.9), which is the norm for modern bars from accredited refiners. One troy ounce, the standard unit for gold, is 31.1035 g. It is heavier than the ordinary ounce used in kitchens (about 28.35 g), which surprises many first-time buyers.

Conversions use 1 troy oz = 31.1035 g. "Minted" bars are stamped from a strip of gold and polished; "cast" bars are poured into a mould. Our troy ounce converter handles other weights.

You will also see a few regional sizes. Tola bars (one tola is about 11.66 g) are common in India, the Gulf and Singapore, and some refiners sell 2 oz bars. These follow the same pricing logic as their nearest metric neighbours.

How big is each gold bar in millimetres?

Gold is very dense, so bars are smaller than most people expect: a 1 kg bar is about the size of a smartphone. Dimensions vary by refiner and by whether a bar is minted or cast, so we only list sizes that refiners publish on their own product pages. Where a refiner gives no figure, we leave the cell out rather than guess.

Sources: Royal Mint and Perth Mint product specification tabs. The Perth Mint states maximum dimensions within its manufacturing tolerances, so individual bars can be slightly smaller. The Royal Mint does not publish thickness for these bars.

The 400 oz Good Delivery bar is in a class of its own. LBMA's technical specifications call for a top surface about 250 mm long (plus or minus 40 mm) and 70 mm wide (plus or minus 15 mm), and a height of about 35 mm (plus or minus 10 mm). Our explainer on Good Delivery gold covers why these bars matter even if you never own one.

How much is each size of gold bar worth today?

The figures below multiply each bar's fine gold weight by the live spot price, which is the wholesale market price for gold. They update automatically.

Spot-based melt values, not dealer prices. Last updated: Loading. A real Good Delivery bar's value depends on its exact fine weight, which can be anywhere from 350 to 430 oz.

Why do small gold bars cost more per gram?

Every bar carries a premium, the amount you pay above the value of its gold. Part of the premium covers the refiner's cost of making, stamping, packaging and certifying the bar, and part is the dealer's margin. Those costs do not fall in line with weight: striking and sealing a 1 g bar in a tamper-evident card takes about as much work as a 20 g bar. So the smaller the bar, the bigger the premium as a share of its gold value. Minted bars also tend to cost a little more than cast bars of the same weight, because of the extra finishing.

Worked example: cast vs minted 1 oz bars in Australia

On 11 October 2026 the Perth Mint's own shop listed its 1 oz cast bar at A$6,184.39, while spot was A$6,012.71 per ounce. That is a premium of A$171.68, or 2.86%. Its 1 oz minted Swan bar cost A$6,214.39, a 3.35% premium. Worked out per gram, the cast bar cost about A$198.83 and the minted bar about A$199.80, against a gold value of about A$193.31 per gram. Same weight, same purity, same maker: the minted finish added about A$30.

Prices from the Perth Mint's online shop, single bar. Premium = price / (fine oz x spot) - 1. More dated checks are on our premium tracker.

What happens when you sell back?

The other half of the cost is the buyback, the price a dealer pays you. On 11 October 2026 Hatton Garden Metals in London listed the same buyback rate for every gold bar size from 1 g to 1 kg: 4.27% below gold value. Its 1 oz bar buyback was £3,035.53, which it showed as 4.29% below gold value. This matters for choosing a size. If the sell-back discount is the same percentage whatever the size, the extra premium you pay on a small bar is simply lost when you sell. The gap between buy and sell prices, called the spread, is the real cost of owning gold, and it shrinks as bars get bigger only because the buying premium shrinks.

Which gold bar size suits whom?

A common middle path is to hold several 1 oz or 100 g bars rather than one kilo bar, so you can sell some without selling everything. Coins are another option at the 1 oz level; our gold coins vs gold bars guide compares the two. If you are new to the whole process, start with how to buy gold, which covers choosing a dealer, paying and storage.

Common mistakes when choosing a gold bar size

• Confusing troy and ordinary ounces. A "1 oz" gold bar holds 31.1 g, not 28.35 g.
• Comparing prices per bar instead of per gram. A 20 g bar and a 1 oz bar are close in weight, so always divide the price by fine grams before comparing.
• Buying lots of tiny bars to save money. Ten 10 g bars almost always cost more than one 100 g bar.
• Removing minted bars from their card. The sealed card links the bar to its assay certificate (a refiner's statement of weight and purity). Dealers may pay less for loose bars. See what an assay card is.
• Ignoring the refiner. Bars from refiners on the LBMA Good Delivery list are the easiest to resell. Compare brands in all gold bar guides.

How are gold bars taxed in the US, UK, Canada and Australia?

Size does not change how a bar is taxed, but purity does. The rules below apply to bars of 99.5% purity or more, which covers almost all modern bullion bars.

In the United States, dealers report some sales back to them on Form 1099-B, including gold bars totalling a kilo or more, so very large bars bring paperwork. Bars of at least 99.5% can be held in a self-directed IRA if a trustee holds them. See where to buy gold in the US for state-by-state context. In the United Kingdom, the lack of VAT makes bars and coins similar on purchase, but only UK legal tender coins escape Capital Gains Tax, which is why many UK buyers above the annual exempt amount prefer coins. Our guide to where to buy gold in the UK covers dealers and tax together. In Canada and Australia, the 99.5% test is the key line: almost all bars pass it, while 22 carat coins do not. Local dealers and prices are covered in where to buy gold in Canada and where to buy gold in Australia.

This is general information, not tax advice. Personal circumstances change the answer, so check with the relevant tax authority or an adviser before a large purchase or sale.

Not financial advice. GoldVetted provides general information to help you compare options. It is not personal financial, tax or legal advice. Gold prices go down as well as up, and you may get back less than you pay. Check tax rules with the official source or a qualified adviser before you act.