What Is Gold Bullion? Gold Bars, Weights, Sizes & Value Explained

Gold bullion is physical gold valued primarily according to its weight, purity and the prevailing gold price. It is commonly produced as gold bars and bullion coins in standardised sizes ranging from small fractional products through to kilogram bars and much larger institutional bars.

For someone new to physical gold, terms such as bullion, troy ounce, .9999 fine gold, spot price and 400oz gold bar can make a relatively simple product sound unnecessarily complicated.

This guide explains what gold bullion is, how much gold bars weigh, how their value is calculated, what common gold bar sizes are available and how physical gold bullion is typically bought in Australia.

01
Gold Bullion Physical gold valued primarily for its precious-metal content.
02
Gold Bar Weights From small gram-denominated bars through to kilogram and institutional bars.
03
Gold Purity Investment-grade gold bullion is commonly produced in very high fineness.
04
Gold Bar Value Primarily determined by fine-gold content, spot price and the bullion premium.
PHYSICAL GOLD BULLION

Compare Gold Bullion Before You Buy

View current gold pricing and compare available bullion products by premium, weight and price per ounce.

What Is Gold Bullion?

Gold bullion is physical gold whose value is based primarily on the quantity and purity of the gold it contains.

Gold bullion is most commonly produced as gold bars and bullion coins. Unlike jewellery, decorative gold objects or many collectable coins, bullion is generally bought and sold with reference to the underlying market value of the gold.

A one-ounce gold bullion bar, for example, contains a specified amount of fine gold. Its market value therefore moves closely with the price of gold, although the finished physical product will normally trade above its underlying metal value due to manufacturing, distribution and dealer costs.

SIMPLE DEFINITION Gold bullion = physical gold held primarily for its precious-metal value.

The most common forms are bullion bars and bullion coins.

What Does “Bullion” Mean?

The term bullion generally refers to precious metal held in a recognised physical form where its value is primarily linked to the amount of metal it contains.

Bullion can include:

999.9 FINE GOLD

Gold Bars

Manufactured in gram, ounce and kilogram-denominated sizes and typically valued primarily according to their fine-gold content.

1 OZ GOLD

Gold Bullion Coins

Coins issued primarily for precious-metal investment, often by sovereign or government-owned mints.

Bullion should not automatically be confused with every object made from gold. Jewellery, medals, numismatic coins and decorative products can derive substantial value from craftsmanship, rarity, design or collectability rather than simply their metal content.

How Much Does a Gold Bullion Bar Weigh?

There is no single weight for a gold bullion bar. Retail gold bars are manufactured in many different sizes, from fractions of a gram through to one kilogram and beyond.

Some of the most common retail gold bar sizes include:

Gold Bar Size Weight in Grams Approx. Troy Ounces
1g 1 gram 0.0322 oz
2.5g 2.5 grams 0.0804 oz
5g 5 grams 0.1608 oz
10g 10 grams 0.3215 oz
20g 20 grams 0.6430 oz
1oz 31.1035 grams 1.0000 oz
50g 50 grams 1.6075 oz
100g 100 grams 3.2151 oz
10oz 311.035 grams 10.0000 oz
1kg 1,000 grams 32.1507 oz
Important:

When precious metals are measured in ounces, the measurement normally refers to troy ounces, not the standard ounce commonly used for everyday goods.

What Are the Most Common Gold Bar Sizes?

Retail gold bullion is available across a wide range of weights because different buyers value affordability, divisibility and lower premiums differently.

1g
Small
Highly divisible
10g
Popular
fractional size
1oz
Common
bullion standard
100g
Larger
retail bar
1kg
Large
bullion holding

Smaller gold bars require less capital per individual unit and are easier to divide when selling. Larger bars will often have lower manufacturing costs relative to the amount of gold they contain, which can translate into a lower premium per gram or ounce.

What Is a Troy Ounce of Gold?

Gold and other precious metals are traditionally measured using the troy ounce.

One troy ounce equals approximately:

1 TROY OUNCE 31.1035g of weight

This is heavier than the ordinary or avoirdupois ounce used for many everyday products.

STANDARD OUNCE 28.3495g Common everyday measurement
VS
TROY OUNCE 31.1035g Used for precious metals

This distinction matters when comparing gold prices. A quoted price per ounce of gold refers to a troy ounce, not a standard 28.35-gram ounce.

How Many Ounces of Gold Are in One Kilogram?

One kilogram contains approximately 32.1507 troy ounces.

1,000 grams ÷ 31.1035 grams per troy ounce = 32.1507 troy ounces

A 1kg gold bullion bar therefore contains just over 32.15 troy ounces of gold by weight.

How Much Does a Large Gold Bar Weigh?

The large gold bars commonly shown in bank vaults, films and financial news are very different from the smaller bars normally purchased by retail bullion customers.

Institutional gold markets commonly use large bars of approximately 400 troy ounces.

GOOD DELIVERY ≈ 400 TROY OZ FINE GOLD
INSTITUTIONAL GOLD

Approximately 400 Troy Ounces

At 400 troy ounces, such a bar would weigh roughly 12.4 kilograms. The exact weight of institutional bars can vary within the relevant trading standard.

These bars are generally associated with wholesale and institutional markets rather than ordinary retail bullion purchases.

A retail buyer asking “How much does a gold bar weigh?” could therefore be referring to anything from a one-gram minted bar to a kilogram cast bar or a much larger institutional bar.

How Much Is a Gold Bullion Bar Worth?

The underlying value of a gold bullion bar is determined primarily by the amount of fine gold it contains and the current market price of gold.

Gold Weight × Current Gold Price = Underlying Metal Value

If a bar contains exactly one troy ounce of fine gold, its underlying metal value is approximately equal to the current gold spot price per ounce.

A finished physical bar will normally have a retail price above that value because the product also carries a bullion premium.

Underlying Gold Value Fine-gold weight × current gold price
+
Bullion Premium Manufacturing, logistics, distribution & margin
=
Retail Gold Bar Price The amount paid for the finished physical product

For a detailed explanation of premiums, price per ounce and buyback spreads, see our guide: How to Compare Bullion Prices in Australia .

What Determines the Price of a Gold Bullion Bar?

Several components can affect the final price of physical gold bullion.

Gold Spot Price The underlying market value of the gold.
AUD/USD Exchange Rate International gold is commonly quoted in US dollars, while Australian buyers pay in AUD.
Gold Weight The quantity of fine gold contained in the product.
Purity The fineness of the gold contained in the bar or coin.
Manufacturing Premium Minting, casting, assay packaging and production costs.
Supply & Demand Wholesale and retail availability can affect physical bullion premiums.

This is why two gold bars containing the same amount of fine gold can have different retail prices.

How Much Is a Gold Bullion Bar?

There is no single price for a gold bullion bar because gold bars are available in many different weights.

A 1g bar contains only a small fraction of a troy ounce, while a 1kg bar contains more than 32 troy ounces of gold. Their total prices are therefore dramatically different even when the price of gold itself is unchanged.

A BETTER WAY TO COMPARE GOLD BARS

Instead of asking only:

“How much does the gold bar cost?”

also ask:

“What is the premium above its underlying gold value?”

Comparing bullion premiums makes it possible to evaluate products of different brands and sizes on a more consistent basis.

Compare current gold bullion premiums →

What Purity Is Gold Bullion?

Gold bullion is commonly produced to a very high level of purity, often expressed as fineness.

999 99.9% fine gold
999.9 99.99% fine gold
9999 99.99% another common notation

A bar marked 999.9 FINE GOLD, for example, indicates gold with a stated fineness of 99.99%.

Product markings commonly include the manufacturer, weight, metal and fineness. Minted bars may also include an individual serial number or be sealed in assay packaging.

Is Gold Bullion 24 Carat?

High-purity investment gold bullion is often described as 24 carat gold. However, carat and fineness are different systems for describing gold purity.

CARAT SYSTEM 24k

A traditional purity scale where 24 carat represents essentially pure gold.

FINENESS SYSTEM 999.9

Expresses the proportion of pure gold in parts per thousand.

Bullion products are commonly described using fineness because it provides a precise indication of the precious-metal content.

What Is the Difference Between Cast and Minted Gold Bars?

Gold bullion bars can be manufactured using different production methods. Two of the most common forms are cast bars and minted bars.

CAST GOLD BAR
FINE GOLD 999.9

Cast Bars

Gold is poured into a mould and allowed to solidify. Cast bars often have a more traditional, individual appearance and are common in larger bullion sizes.

MINTED GOLD BAR
10g 999.9 GOLD

Minted Bars

Manufactured with more controlled dimensions and finishes and often supplied in protective assay packaging. Smaller retail bars are frequently produced in this format.

Both formats can contain the same quantity and purity of gold. The difference is primarily in manufacturing method, presentation and potentially the premium paid.

Why Are Gold Bars Made in Different Sizes?

Different gold bar sizes allow buyers to balance three competing considerations: purchase amount, premium and divisibility.

SMALLER BARS 1g – 10g
  • Lower total purchase price per bar
  • High divisibility
  • Easy to sell in small quantities
  • Usually higher premium per gram
MID-SIZE BARS 20g – 100g
  • Balance between size and divisibility
  • Lower unit count
  • Often more efficient premiums
  • Still manageable retail sizes
LARGER BARS 250g – 1kg
  • Large gold content per unit
  • Efficient storage
  • Often lower premium per ounce
  • Less divisible when selling

A larger bar is not automatically better simply because its premium is lower. Someone who wants the ability to sell their gold in smaller increments may deliberately choose multiple smaller products.

Gold Bars vs Gold Bullion Coins

Gold bullion does not have to be held in bar form. Sovereign bullion coins are another widely recognised form of physical gold.

Feature Gold Bars Gold Bullion Coins
Typical premium Often lower Can be higher
Legal tender No Commonly yes
Available sizes Very broad Broad
Storage efficiency Excellent Good
Divisibility Depends on bar size Strong in fractional sizes
Collectable potential Usually secondary Can be higher

Neither format is universally superior. A buyer focused primarily on low premiums may prefer bars, while another buyer may value the recognition, design or fractional sizes offered by bullion coins.

Does the Brand of a Gold Bar Matter?

Brand can matter, particularly in terms of product recognition, manufacturing quality, authentication features and market familiarity.

Recognised bullion manufacturers commonly stamp or display:

  • Manufacturer or refinery name
  • Metal type
  • Gold weight
  • Purity or fineness
  • Serial number on some products
  • Assay information where applicable

However, paying a larger premium for a particular brand does not automatically mean the underlying gold is worth proportionately more.

Two 1oz bars of the same fineness can contain effectively the same amount of gold while trading at different retail premiums.

How to Buy Gold Bullion in Australia

Buying physical gold bullion is relatively straightforward once the pricing structure is understood.

  1. 1
    Check the Current Gold Price

    Start by understanding the current Australian-dollar value of gold.

  2. 2
    Choose Bars or Coins

    Decide whether your priority is premium, divisibility, recognition or a combination of these.

  3. 3
    Choose a Gold Weight

    Compare smaller fractional products with larger ounce or gram-denominated bars.

  4. 4
    Compare the Bullion Premium

    Look beyond the total product price and compare what you are paying above the value of the gold.

  5. 5
    Review Availability

    The lowest-premium product can change as wholesale supply and dealer inventory change.

  6. 6
    Arrange Delivery, Collection or Storage

    Consider how the physical bullion will be received and securely stored.

How Should You Compare Gold Bullion Prices?

Comparing gold bullion by total price alone can be misleading because different products contain different quantities of gold.

A more useful comparison considers:

Gold Weight Gold Purity Metal Value Retail Price Total Premium Premium % Premium Per Ounce Buyback Value

The Coin Chest’s bullion premium comparison allows available products to be compared against their underlying precious-metal value.

USEFUL COMPARISON

Don’t Just Compare Gold Bar Prices

Compare how much of the purchase price represents actual gold and how much represents the physical-product premium.

KEY METRIC How much am I paying above the underlying gold value?
FREQUENTLY ASKED QUESTIONS

Gold Bullion FAQs

What is gold bullion?

Gold bullion is physical gold valued primarily according to its weight, purity and the prevailing gold price. It is commonly produced as gold bars and bullion coins.

What is a gold bullion bar?

A gold bullion bar is a manufactured physical bar containing a specified weight and purity of gold. Its value is closely linked to the value of the fine gold it contains, plus any premium applied to the finished product.

How much does a gold bullion bar weigh?

Gold bullion bars do not have one standard retail weight. Common sizes include 1g, 2.5g, 5g, 10g, 20g, 1oz, 50g, 100g, 10oz and 1kg. Institutional gold bars can be substantially larger.

How heavy is a gold bullion bar?

It depends on the bar. A one-ounce gold bar weighs approximately 31.1035 grams, while a one-kilogram bar weighs 1,000 grams and contains approximately 32.1507 troy ounces.

How much does gold bullion weigh?

Gold bullion is available in many weights. Small retail products can weigh only one gram, while large retail bars can weigh one kilogram. Institutional bars can weigh around 400 troy ounces.

How much is a gold bullion bar?

The price depends primarily on the amount of fine gold contained in the bar, the current gold price and the bullion premium charged for the physical product. A larger bar therefore costs substantially more in total than a small fractional bar.

How much is a gold bullion bar worth?

Its underlying metal value is calculated using the quantity of fine gold it contains and the current gold price. The amount received when selling may differ depending on the dealer’s current buyback rate and the specific product.

Is gold bullion pure gold?

Many investment-grade gold bullion products are manufactured to very high fineness, commonly 99.9% or 99.99% gold. The exact purity should be checked on the individual product.

Is gold bullion 24 carat?

Very high-purity investment gold is commonly described as 24 carat. Bullion products are often marked using a more precise fineness measurement such as 999.9 rather than only a carat rating.

What does 999.9 gold mean?

999.9 fineness indicates gold with a stated purity of 999.9 parts per thousand, equivalent to 99.99% gold.

How many grams are in one ounce of gold?

One troy ounce of gold weighs approximately 31.1035 grams. Precious metals use the troy-ounce system rather than the ordinary 28.35-gram ounce.

How many ounces of gold are in one kilogram?

One kilogram contains approximately 32.1507 troy ounces.

What is the standard gold bar size?

There is no single standard retail gold bar size. One-ounce bars are widely recognised, but gram-denominated products and larger bars such as 100g and 1kg are also common.

How much does a 400oz gold bar weigh?

A 400-troy-ounce gold bar weighs approximately 12.4 kilograms. Large bars of this general size are associated primarily with institutional and wholesale gold markets rather than ordinary retail purchases.

Can you buy small gold bars?

Yes. Gold bars are available in small fractional sizes such as 1g, 2.5g, 5g and 10g. Smaller bars provide greater divisibility but commonly carry a higher premium relative to the amount of gold contained.

Where can I buy gold bullion in Australia?

Gold bullion can be purchased from specialist precious-metal and bullion dealers. Before purchasing, compare the product’s purity, weight, premium, availability, payment costs and delivery or storage arrangements.

THE COIN CHEST BULLION TOOLS

Understand the Gold Before You Compare the Price

A gold bar’s total price tells only part of the story. Weight, purity, current metal value and premium determine how much gold you are actually receiving for the amount spent.

Start with the underlying metal.

Then compare the premium you’re paying to own it in physical form.