<p>An ounce of gold is smaller than many people expect. It contains 31.1 grams of metal that fills about 1.61 cubic centimeters (cm³), or about the space of two stacked quarters. Pressed into a coin, an ounce of gold is about the size of a half dollar.</p>
<p>If the gold is crafted into a bar, it usually is about 41 x 24 mm. That is roughly one-fifth the face of a credit card.</p>
<p>You may have read that a 1 oz gold coin is the size of a quarter, but that is not true. Most 1 oz gold coins are a little wider than a half dollar. This guide shows the real sizes, where each number comes from, and how to check a coin at home with a ruler and a scale.</p>
<h2>Quick facts: one troy ounce of gold</h2>
<ul>
<li>Weight: 31.1035 grams</li>
<li>Volume: 1.61 cm³</li>
<li>As a cube: 11.7 mm on each side</li>
<li>As a coin: 30 to 37 mm across</li>
<li>As a bar: about 41 x 24 mm</li>
<li>An ounce of silver: 1.84 times bigger</li>
</ul>
<!– Image placeholder from draft: Original photo of a 1 oz gold coin and a 1 oz gold bar on a ruler, next to a quarter and a half dollar. –>
<h2>How Big Is an Ounce of Gold?</h2>
<p>Every size on this page starts with one number, and that number is volume.</p>
<p>Gold is one of the densest metals you can buy. The Royal Society of Chemistry lists its <a href="https://periodic-table.rsc.org/element/79/gold">density at 19.3 grams per cm³</a>. If you divide one troy ounce (31.1035 g) by 19.3, you get 1.61 cm³ of metal.</p>
<p>If you melted that ounce into a cube, each side would be just 11.7 mm long, which is less than half an inch. However, you do not find gold sold in cubes. Mints and refiners press gold flat to shape it into either coins or bars. The more useful question is not, “how big is an ounce of gold?” but rather how an ounce compares to the coins in your pocket.</p>
<h3>The Half Dollar Test</h3>
<p>Picture a solid gold disc as wide as a half dollar, which is <a href="https://www.usmint.gov/learn/coins-and-medals/circulating-coins/coin-specifications">30.61 mm across</a>. To hold one ounce, that disc would need to be 2.19 mm thick. That is almost the same as a real half dollar at 2.15 mm.</p>
<p>So an ounce of gold has about the same shape as a half dollar. The difference between them is the weight. A half dollar weighs 11.34 g. In contrast, a full gold ounce coin weighs 2.7 times as much.</p>
<h3>Why "The Size of a Quarter" Is Wrong</h3>
<p>A quarter is <a href="https://www.usmint.gov/learn/coins-and-medals/circulating-coins/coin-specifications">24.26 mm wide and 1.75 mm thick</a>. If you squeezed an ounce of gold down to its width, it would be 3.49 mm thick. That makes it about twice as thick as a quarter.</p>
<p>In other words, an ounce of gold takes up the space of two stacked quarters but weighs as much as five and a half of them. That is why a gold coin feels so heavy when you hold it.</p>
<h3>Troy Ounces vs. Kitchen Ounces</h3>
<p>Dealers weigh gold in <a href="https://www.moneymetals.com/measurement/what-is-a-troy-ounce">troy ounces</a>, not the ounces on a kitchen scale. One troy ounce is 31.1035 grams, while a kitchen ounce is 28.35 grams. A troy ounce is about 10% heavier. To see the full conversion, see <a href="https://www.moneymetals.com/measurement/how-many-grams-in-1-oz-of-gold">how many grams are in a 1 oz gold bar</a>.</p>
<h2>What Does a 1 oz Gold Coin Look Like?</h2>
<p>A 1 oz gold coin is about the size of a half dollar. Most of them are 30 to 32.7 mm across, and the Austrian Philharmonic is the odd one out at 37 mm. Most are also 2 to 3 mm thick at the rim.</p>
<p>The <a href="https://en.wikipedia.org/wiki/American_Gold_Eagle">Gold Eagle</a> is 2.87 mm thick, while the wide, thin <a href="https://en.wikipedia.org/wiki/Vienna_Philharmonic_(coin)">Philharmonic</a> is just 2 mm.</p>
<p>U.S. law even spells out the Gold Eagle's size. Under <a href="https://www.law.cornell.edu/uscode/text/31/5112">31 U.S.C. 5112</a>, the $50 gold coin is "32.7 millimeters in diameter" and "weighs 33.931 grams."</p>
<!– Image placeholder from draft: Actual-size chart of six 1 oz gold coins beside a half dollar, with a 1-inch square to check print or screen scale. –>
<h3>1 oz Gold Coin Size Chart</h3>
<p>Each coin below holds one troy ounce of pure gold. The third column shows how much wider or narrower each coin is than a <a href="https://www.usmint.gov/learn/coins-and-medals/circulating-coins/coin-specifications">30.61 mm half dollar</a>.</p>
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<div class="inline-block min-w-full py-2 align-middle sm:px-6 lg:px-8">
<div class="overflow-hidden rounded-lg border border-slate-800 w-full">
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<thead class="bg-slate-800 text-white">
<tr class="divide-x divide-slate-200">
<th class="p-3 text-left text-sm font-semibold">Coin</th>
<th class="p-3 text-left text-sm font-semibold">Diameter</th>
<th class="p-3 text-left text-sm font-semibold">vs. Half Dollar</th>
<th class="p-3 text-left text-sm font-semibold">Total Weight</th>
<th class="p-3 text-left text-sm font-semibold">Purity</th>
<th class="p-3 text-left text-sm font-semibold">Source</th>
</tr>
</thead>
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<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700"><a href="https://www.moneymetals.com/buy/gold/coins/american-gold-eagle">American Gold Eagle</a></td>
<td class="p-3 text-sm text-slate-700">32.70 mm</td>
<td class="p-3 text-sm text-slate-700">2.1 mm wider</td>
<td class="p-3 text-sm text-slate-700">33.931 g</td>
<td class="p-3 text-sm text-slate-700">22k (91.67%)</td>
<td class="p-3 text-sm text-slate-700"><a href="https://www.usmint.gov/coins-precious-metal-coins/bullion-coin-programs/">U.S. Mint</a></td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700"><a href="https://www.moneymetals.com/buy/gold/coins/gold-american-buffalo">American Gold Buffalo</a></td>
<td class="p-3 text-sm text-slate-700">32.70 mm</td>
<td class="p-3 text-sm text-slate-700">2.1 mm wider</td>
<td class="p-3 text-sm text-slate-700">31.103 g</td>
<td class="p-3 text-sm text-slate-700">99.99%</td>
<td class="p-3 text-sm text-slate-700"><a href="https://www.usmint.gov/coins-precious-metal-coins/bullion-coin-programs/">U.S. Mint</a></td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700"><a href="https://www.moneymetals.com/buy/gold/coins/canadian-gold-maple-leaf">Canadian Gold Maple Leaf</a></td>
<td class="p-3 text-sm text-slate-700">30 mm</td>
<td class="p-3 text-sm text-slate-700">0.6 mm narrower</td>
<td class="p-3 text-sm text-slate-700">31.11 g</td>
<td class="p-3 text-sm text-slate-700">99.99%</td>
<td class="p-3 text-sm text-slate-700"><a href="https://www.mint.ca/en/shop/coins/2024/2024-50-1-oz-9999-pure-gold-coin-gml-bullion">Royal Canadian Mint</a></td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700"><a href="https://www.moneymetals.com/buy/gold/coins/krugerrand-south-african-mint">South African Krugerrand</a></td>
<td class="p-3 text-sm text-slate-700">32.77 mm</td>
<td class="p-3 text-sm text-slate-700">2.1 mm wider</td>
<td class="p-3 text-sm text-slate-700">33.93 g</td>
<td class="p-3 text-sm text-slate-700">22k (91.67%)</td>
<td class="p-3 text-sm text-slate-700"><a href="https://en.wikipedia.org/wiki/Krugerrand">Krugerrand specs</a></td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700"><a href="https://www.moneymetals.com/buy/gold/other-world-mints">British Gold Britannia</a></td>
<td class="p-3 text-sm text-slate-700">32.69 mm</td>
<td class="p-3 text-sm text-slate-700">2.1 mm wider</td>
<td class="p-3 text-sm text-slate-700">31.21 g</td>
<td class="p-3 text-sm text-slate-700">99.99%</td>
<td class="p-3 text-sm text-slate-700"><a href="https://www.royalmint.com/collect/archive/britannia-2018-one-ounce-gold-bullion-coin/">Royal Mint</a></td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700"><a href="https://www.moneymetals.com/buy/gold/other-world-mints">Austrian Philharmonic</a></td>
<td class="p-3 text-sm text-slate-700">37 mm</td>
<td class="p-3 text-sm text-slate-700">6.4 mm wider</td>
<td class="p-3 text-sm text-slate-700">31.103 g</td>
<td class="p-3 text-sm text-slate-700">99.99%</td>
<td class="p-3 text-sm text-slate-700"><a href="https://www.royalmint.com/invest/bullion/uk-coin-ranges/world-coins/philharmonic-2024-1oz-gold-bullion-coin/">Royal Mint</a>, <a href="https://en.wikipedia.org/wiki/Vienna_Philharmonic_(coin)">specs</a></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<h3>Why the Same Ounce Comes in Different Sizes</h3>
<p>Every coin in the chart holds the same amount of gold, so why don't they match? There are three reasons:</p>
<ul>
<li><strong>Alloy.</strong> The Gold Eagle and Krugerrand are 22-karat coins. The Eagle is <a href="https://www.usmint.gov/coins-precious-metal-coins/bullion-coin-programs/">91.67% gold, 3% silver, and the rest copper</a>. That adds 2.83 g of other metal on top of a full ounce of gold, which is why the coin weighs 33.93 g.</li>
<li><strong>Design.</strong> Each mint picks its own shape. The Philharmonic spreads its ounce into a wide, thin 37 mm disc, while the Maple Leaf packs the same ounce into 30 mm.</li>
<li><strong>Rims.</strong> Mints measure coin thickness at the raised rim, and the flat field and design sit lower. As a result, a coin looks a bit bulkier than the gold inside it.</li>
</ul>
<h3>Color: 22-Karat vs. .9999 Gold</h3>
<p>Gold alloys can also change the color. The more copper there is in a gold product, the <a href="https://en.wikipedia.org/wiki/Colored_gold">redder it can turn the metal</a>. The alloys of the Gold Eagle and Krugerrand have more copper, giving them a warm, orange tone.</p>
<p>This is in contrast to pure .9999 gold coins like the Buffalo and Maple Leaf. These coins have a much brighter and more yellow hue. The copper also makes 22k gold <a href="https://en.wikipedia.org/wiki/Krugerrand">more durable than pure gold</a>, so these coins resist scratches better than their finer counterparts.</p>
<h2>What Does a 1 oz Gold Bar Look Like?</h2>
<p>A 1 oz gold bar is a thin, flat rectangle. One common bar, the <a href="https://www.moneymetals.com/buy/gold/pamp-suisse-gold-bars">PAMP Suisse</a> Lady Fortuna, is <a href="https://www.apmex.com/resources/ProductSpecifications/1-oz-PAMP-Suisse-Lady-Fortuna-Gold-Bar-APMEX-11951.pdf">41 x 24 mm and 1.71 mm thick</a>. A credit card is <a href="https://en.wikipedia.org/wiki/ISO/IEC_7810">85.60 x 53.98 mm</a>, so the bar covers about 21% of a card’s face.</p>
<p>There is no standard size, because each refiner picks its own. One dealer, for example, lists a Valcambi 1 oz bar at <a href="https://goldbroker.com/buy/gold/bars/1-ounce-gold-bar-valcambi-51">38 x 22 mm</a>. Both bars hold the same ounce of gold. Since the Valcambi has a smaller face, it has to be a little thicker.</p>
<p>Most small bars are minted. Refiners shape these bars by <a href="https://www.moneymetals.com/measurement/how-much-does-a-gold-bar-weigh">cutting them from rolled sheets of gold</a>, then stamping them with a proprietary design. Minted bars have a clean, crisp look. Cast bars start as molten gold poured into molds. Their casting process gives them a rougher, more rugged look.</p>
<p>Many minted bars come sealed in a plastic assay card. The card shows the weight, purity, refiner, and serial number. The card is much bigger than the bar, so don’t judge the bar’s size by its packaging. We provide several examples on our <a href="https://www.moneymetals.com/buy/gold/bars/1-oz-gold-bars">1 oz gold bars</a> page.</p>
<!– Image placeholder from draft: Original photo of a 1 oz minted bar in its assay card, and the same bar out of the card on a credit card. –>
<h3>Why Listed Bar Thickness Can Mislead</h3>
<p>Sellers often list bar thickness at the thickest point, such as a raised rim. You can check any listing with simple math:</p>
<ol>
<li>Multiply the length, width, and thickness in mm.</li>
<li>Divide by 1,000 to get cm³.</li>
<li>Compare the result with 1.61 cm³, the volume of one ounce.</li>
</ol>
<p>For example, let’s examine a PAMP bar. At 41 x 24 x 1.71 mm, that bar measures 1.68 cm³, and a solid block that size would weigh 32.5 g. That is close to one ounce; rounded edges and a raised rim make up the difference.</p>
<p>Now take a listing that says 42 x 24 x 2 mm. That works out to 2.02 cm³, and a solid gold bar that size would weigh 38.9 g, or 25% more than an ounce. So the 2 mm figure must be the rim, not the average thickness.</p>
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<th class="p-3 text-left text-sm font-semibold">Bar</th>
<th class="p-3 text-left text-sm font-semibold">Size</th>
<th class="p-3 text-left text-sm font-semibold">Listed Thickness</th>
<th class="p-3 text-left text-sm font-semibold">Average Thickness Needed for 1 oz</th>
</tr>
</thead>
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<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">PAMP Suisse Lady Fortuna</td>
<td class="p-3 text-sm text-slate-700">41 x 24 mm</td>
<td class="p-3 text-sm text-slate-700"><a href="https://www.apmex.com/resources/ProductSpecifications/1-oz-PAMP-Suisse-Lady-Fortuna-Gold-Bar-APMEX-11951.pdf">1.71 mm</a></td>
<td class="p-3 text-sm text-slate-700">1.64 mm</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Valcambi</td>
<td class="p-3 text-sm text-slate-700">38 x 22 mm</td>
<td class="p-3 text-sm text-slate-700"><a href="https://goldbroker.com/buy/gold/bars/1-ounce-gold-bar-valcambi-51">Not listed</a></td>
<td class="p-3 text-sm text-slate-700">1.93 mm</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<h3>A Kilo Bar for Scale</h3>
<p>A kilo bar holds <a href="https://www.moneymetals.com/measurement/how-many-troy-ounces-in-a-kilo">32.15 troy ounces</a>. Its gold fills a volume of roughly 51.8 cm³. That is 32 times the metal in a 1 oz bar. You can see a list of gold bar weights from 1 gram to 400 ounces on our <a href="https://www.moneymetals.com/measurement/how-much-does-a-gold-bar-weigh">how much a gold bar weighs page</a>.</p>
<h2>What 1/2, 1/4, and 1/10 oz Gold Coins Look Like</h2>
<p>Fractional gold coins are where the quarter comparison fits. A quarter falls between the 1/2 oz and 1/4 oz Gold Eagles in size, and a 1/10 oz Gold Eagle is smaller than a dime.</p>
<p>The chart below runs from largest to smallest. Gold Eagle sizes come from <a href="https://www.law.cornell.edu/uscode/text/31/5112">31 U.S.C. 5112</a>, and the other coin sizes come from the <a href="https://www.usmint.gov/learn/coins-and-medals/circulating-coins/coin-specifications">U.S. Mint</a>.</p>
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<div class="inline-block min-w-full py-2 align-middle sm:px-6 lg:px-8">
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<th class="p-3 text-left text-sm font-semibold">Coin</th>
<th class="p-3 text-left text-sm font-semibold">Diameter</th>
<th class="p-3 text-left text-sm font-semibold">Gold Content</th>
</tr>
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<td class="p-3 text-sm text-slate-700">1 oz Gold Eagle</td>
<td class="p-3 text-sm text-slate-700">32.7 mm</td>
<td class="p-3 text-sm text-slate-700">1 oz</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Half dollar</td>
<td class="p-3 text-sm text-slate-700">30.61 mm</td>
<td class="p-3 text-sm text-slate-700">None</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">1/2 oz Gold Eagle</td>
<td class="p-3 text-sm text-slate-700">27.0 mm</td>
<td class="p-3 text-sm text-slate-700">1/2 oz</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Dollar coin</td>
<td class="p-3 text-sm text-slate-700">26.49 mm</td>
<td class="p-3 text-sm text-slate-700">None</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Quarter</td>
<td class="p-3 text-sm text-slate-700">24.26 mm</td>
<td class="p-3 text-sm text-slate-700">None</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">1/4 oz Gold Eagle</td>
<td class="p-3 text-sm text-slate-700">22.0 mm</td>
<td class="p-3 text-sm text-slate-700">1/4 oz</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Nickel</td>
<td class="p-3 text-sm text-slate-700">21.21 mm</td>
<td class="p-3 text-sm text-slate-700">None</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Dime</td>
<td class="p-3 text-sm text-slate-700">17.91 mm</td>
<td class="p-3 text-sm text-slate-700">None</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">1/10 oz Gold Eagle</td>
<td class="p-3 text-sm text-slate-700">16.5 mm</td>
<td class="p-3 text-sm text-slate-700">1/10 oz</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<!– Image placeholder from draft: "Coin ladder" graphic showing all nine coins to scale in a row. –>
<p>The advantage of smaller coins is that they let you buy gold in smaller, more manageable amounts. You can browse our <a href="https://www.moneymetals.com/buy/gold/fractionals">fractional gold coins</a> to see the full range.</p>
<h2>How Big Is an Ounce of Silver?</h2>
<p>Silver is far less dense than gold. Silver has a density of roughly <a href="https://periodic-table.rsc.org/element/47/silver">10.5 g per cm³</a>, so an ounce of silver fills 2.96 cm³. That is 1.84 times the space of an ounce of gold.</p>
<p>You can see this gap when you look at coins. A 1 oz <a href="https://www.moneymetals.com/2026-silver-american-eagle-1-troy-ounce-999-pure/2728">Silver Eagle</a> is <a href="https://www.usmint.gov/coins-precious-metal-coins/bullion-coin-programs/">40.6 mm across</a>. In contrast, a 1 oz Gold Eagle is only 32.7 mm.</p>
<p>Platinum goes the other way. At <a href="https://periodic-table.rsc.org/element/78/platinum">21.5 grams per cm³</a>, an ounce of platinum fills just 1.45 cm³. That is roughly 10% less space than an ounce of gold contains.</p>
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<thead class="bg-slate-800 text-white">
<tr class="divide-x divide-slate-200">
<th class="p-3 text-left text-sm font-semibold">Metal</th>
<th class="p-3 text-left text-sm font-semibold">Density</th>
<th class="p-3 text-left text-sm font-semibold">Volume of 1 oz</th>
<th class="p-3 text-left text-sm font-semibold">Side of a 1 oz Cube</th>
</tr>
</thead>
<tbody class="divide-y divide-slate-200 bg-white">
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Silver</td>
<td class="p-3 text-sm text-slate-700">10.5 g/cm³</td>
<td class="p-3 text-sm text-slate-700">2.96 cm³</td>
<td class="p-3 text-sm text-slate-700">14.4 mm</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Gold</td>
<td class="p-3 text-sm text-slate-700">19.3 g/cm³</td>
<td class="p-3 text-sm text-slate-700">1.61 cm³</td>
<td class="p-3 text-sm text-slate-700">11.7 mm</td>
</tr>
<tr class="divide-x divide-slate-200 even:bg-slate-50">
<td class="p-3 text-sm text-slate-700">Platinum</td>
<td class="p-3 text-sm text-slate-700">21.5 g/cm³</td>
<td class="p-3 text-sm text-slate-700">1.45 cm³</td>
<td class="p-3 text-sm text-slate-700">11.3 mm</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<!– Image placeholder from draft: A 1 oz gold cube and a 1 oz silver cube side by side, to scale. –>
<h2>How to Check a 1 oz Gold Coin With a Ruler and a Scale</h2>
<p>One of the top search results for this topic is a Reddit post where a buyer weighed a coin and asked, <a href="https://www.reddit.com/r/Gold/comments/1ntuwca/is_this_considered_1_oz/">“Is this considered 1 oz?”</a> A digital scale and a set of calipers can answer that question, and our guide to <a href="https://www.moneymetals.com/guides/how-to-test-gold-and-silver-at-home">testing gold at home</a> recommends both.</p>
<p><strong>Step 1: Weigh it.</strong> Use a digital scale, and compare the reading with the coin's total weight, not its gold content.</p>
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<th class="p-3 text-left text-sm font-semibold">Coin</th>
<th class="p-3 text-left text-sm font-semibold">Expected Scale Reading</th>
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<td class="p-3 text-sm text-slate-700">American Gold Eagle</td>
<td class="p-3 text-sm text-slate-700">33.93 g</td>
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<td class="p-3 text-sm text-slate-700">South African Krugerrand</td>
<td class="p-3 text-sm text-slate-700">33.93 g</td>
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<td class="p-3 text-sm text-slate-700">British Gold Britannia</td>
<td class="p-3 text-sm text-slate-700">31.21 g</td>
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<td class="p-3 text-sm text-slate-700">Canadian Gold Maple Leaf</td>
<td class="p-3 text-sm text-slate-700">31.11 g</td>
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<td class="p-3 text-sm text-slate-700">American Gold Buffalo</td>
<td class="p-3 text-sm text-slate-700">31.10 g</td>
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<td class="p-3 text-sm text-slate-700">Austrian Philharmonic</td>
<td class="p-3 text-sm text-slate-700">31.10 g</td>
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<p>A Gold Eagle that reads 33.9 g is correct, because it holds a full ounce of gold plus 2.83 g of alloy. Don't expect it to read 31.1 g. Cheap scales also round their readings, so tiny gaps are normal.</p>
<p><strong>Step 2: Measure it.</strong> Use a ruler or calipers across the widest point, and compare the result with the size chart above. Small wear is normal, but a big gap is a red flag.</p>
<p><strong>Step 3: Know the limits.</strong> Tungsten is almost as dense as gold. According to The Royal Society of Chemistry, tungsten has a density of <a href="https://periodic-table.rsc.org/element/74/tungsten">19.3 g per cm³</a>. That is the same figure it gives for gold. That means a tungsten-core fake can match both size and weight. If anything seems off, try the stronger tests in our <a href="https://www.moneymetals.com/guides/how-to-test-gold-and-silver-at-home">home testing guide</a>, or buy from a dealer you trust.</p>
<h2>What Does an Ounce of Gold Look Like in Jewelry?</h2>
<p>Jewelry is rarely pure gold. Instead, jewelry measures gold by the karat system, with karat ratings showing how much gold is in an item. For example, <a href="https://www.moneymetals.com/guides/how-to-test-gold-and-silver-at-home">14k gold is about 58.5% gold, and 18k is about 75% gold</a>. Because the other metals add bulk, the same ounce of gold looks bigger in a ring or chain than it does in a coin.</p>
<h3>Frequently Asked Questions</h3>
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<p>No. A quarter is <a href="https://www.usmint.gov/learn/coins-and-medals/circulating-coins/coin-specifications">24.26 mm across</a>, while a 1 oz gold coin is 30 to 37 mm across. That makes it closer to a half dollar, which is 30.61 mm. The 1/2 oz and 1/4 oz Gold Eagles are the coins that come closest to quarter size.</p>
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<h4 class="text-xl font-semibold"><button id="controlsAccordionItemTwo" type="button" class="flex w-full cursor-pointer items-center justify-between gap-2 bg-slate-200 p-4 text-left underline-offset-2 duration-200 hover:bg-slate-100 focus-visible:bg-slate-50 focus-visible:underline focus-visible:outline-hidden" aria-controls="accordionItemTwo" x-on:click="isExpanded = ! isExpanded" x-bind:class="isExpanded ? 'font-bold' : 'font-medium'" x-bind:aria-expanded="isExpanded ? 'true' : 'false'"> <span>How big is a troy ounce of gold?</span> <svg xmlns="http://www.w3.org/2000/svg" viewbox="0 0 24 24" fill="none" stroke-width="2" stroke="currentColor" class="size-5 shrink-0 transition" aria-hidden="true" x-bind:class="isExpanded ? 'rotate-180' : ''"> <path stroke-linecap="round" stroke-linejoin="round" d="M19.5 8.25l-7.5 7.5-7.5-7.5"></path> </svg> </button></h4>
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<p>Based on gold's <a href="https://periodic-table.rsc.org/element/79/gold">density of 19.3 g per cm³</a>, a troy ounce of gold fills 1.61 cm³. It would form a cube 11.7 mm on each side. As a coin, it is about the size of a half dollar, and as a bar, it is about 41 x 24 mm.</p>
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<h4 class="text-xl font-semibold"><button id="controlsAccordionItemThree" type="button" class="flex w-full cursor-pointer items-center justify-between gap-2 bg-slate-200 p-4 text-left underline-offset-2 duration-200 hover:bg-slate-100 focus-visible:bg-slate-50 focus-visible:underline focus-visible:outline-hidden" aria-controls="accordionItemThree" x-on:click="isExpanded = ! isExpanded" x-bind:class="isExpanded ? 'font-bold' : 'font-medium'" x-bind:aria-expanded="isExpanded ? 'true' : 'false'"> <span>How thick is a 1 oz gold bar?</span> <svg xmlns="http://www.w3.org/2000/svg" viewbox="0 0 24 24" fill="none" stroke-width="2" stroke="currentColor" class="size-5 shrink-0 transition" aria-hidden="true" x-bind:class="isExpanded ? 'rotate-180' : ''"> <path stroke-linecap="round" stroke-linejoin="round" d="M19.5 8.25l-7.5 7.5-7.5-7.5"></path> </svg> </button></h4>
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<p>Most 1 oz gold bars are less than 2 mm thick. The PAMP Lady Fortuna <a href="https://www.apmex.com/resources/ProductSpecifications/1-oz-PAMP-Suisse-Lady-Fortuna-Gold-Bar-APMEX-11951.pdf">is listed at 1.71 mm</a>, and a flat 41 x 24 mm bar needs an average thickness of 1.64 mm to hold one ounce.</p>
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<p>Some mints use 22-karat gold. The Gold Eagle and Krugerrand <a href="https://www.law.cornell.edu/uscode/text/31/5112">weigh 33.93 g</a>, but they still hold one full troy ounce of gold. The extra weight comes from the other metals mixed in to make the coin more durable.</p>
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<h4 class="text-xl font-semibold"><button id="controlsAccordionItemFive" type="button" class="flex w-full cursor-pointer items-center justify-between gap-2 bg-slate-200 p-4 text-left underline-offset-2 duration-200 hover:bg-slate-100 focus-visible:bg-slate-50 focus-visible:underline focus-visible:outline-hidden" aria-controls="accordionItemFive" x-on:click="isExpanded = ! isExpanded" x-bind:class="isExpanded ? 'font-bold' : 'font-medium'" x-bind:aria-expanded="isExpanded ? 'true' : 'false'"> <span>How much is an ounce of gold worth?</span> <svg xmlns="http://www.w3.org/2000/svg" viewbox="0 0 24 24" fill="none" stroke-width="2" stroke="currentColor" class="size-5 shrink-0 transition" aria-hidden="true" x-bind:class="isExpanded ? 'rotate-180' : ''"> <path stroke-linecap="round" stroke-linejoin="round" d="M19.5 8.25l-7.5 7.5-7.5-7.5"></path> </svg> </button></h4>
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<p>The price of gold changes throughout the day. Check the <a href="https://www.moneymetals.com/gold-price">live gold price per ounce</a> for today's spot price.</p>
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