A $20 double eagle contains 0.9675 troy ounce of pure gold, about 30.093 grams. The whole coin weighs 33.436 grams, because it is a 90% gold alloy. That is true of both the Liberty Head and the Saint-Gaudens designs and of every date, because they were all struck to the same legal standard.
Where the number comes from
You do not need a scale to work this out; the law fixes it. The Coinage Act of January 18, 1837 set the standard for U.S. gold coins at nine hundred parts pure gold to one hundred of alloy, and set the $10 eagle at 258 grains. The Act of March 3, 1849 authorized the double eagle “conformably in all respects to the standard for gold coins now established by law,” which makes it twice the eagle: 516 grains.
| Step | Working | Result |
|---|---|---|
| Total weight | 516 grains × 0.0648 g | 33.436 g |
| Gold share | 90% (.900 fine) | 30.093 g of gold |
| In troy ounces | 516 grains × .900 ÷ 480 grains per troy oz | 0.9675 troy oz |
The troy ounce is 480 grains, so you can do the whole calculation in grains without converting anything: 516 × 0.9 ÷ 480 = 0.9675.
How it compares with a one-ounce Gold Eagle
A $20 double eagle and a modern one-ounce American Gold Eagle are almost the same size, but they are not the same coin inside. The Gold Eagle weighs 33.931 g and holds exactly 1 troy ounce of gold in a 22-karat alloy. The double eagle weighs 33.436 g and holds 0.9675 troy ounce: about 3.25% less gold in a coin that weighs about 0.5 g less. The Gold Eagle is heavier because its 91.67% gold share is diluted by more silver and copper. If someone describes a double eagle as “an ounce of gold,” that is a rounding the arithmetic does not support.
What the figure does not tell you
- Wear. The figures are the standard issue weight. A heavily circulated coin has lost a little gold to wear, so it will weigh slightly less than 33.436 g.
- Collector value. Many double eagles are worth more than their gold. Date, mint and condition decide that, and so does a documented history, as the 1933 double eagle shows. The gold content is the floor of the calculation, not the answer.
- Authenticity. A scale and calipers cannot prove a coin is real, because fakes can be made to the right weight and size. For a coin that matters, get it examined by a reputable grading service or dealer before you rely on it.
Work out your own
Gold value = fine troy ounces × the price you type × number of coins. It is the metal only, not what a dealer pays or charges.
Reading about the coin itself? See the story behind the Saint-Gaudens double eagle.
Frequently asked questions about gold in a double eagle
How many grams of gold are in a $20 gold coin?
About 30.093 grams of pure gold, in a coin weighing 33.436 grams in total.
Is a $20 double eagle an ounce of gold?
No. It holds 0.9675 troy ounce, a little under an ounce. The one-ounce gold coins are bullion coins such as the American Gold Eagle.
Do Liberty Head and Saint-Gaudens double eagles have the same gold content?
Yes. Both were struck to the same .900 fine standard at the same weight, so the gold content is the same; the designs and collector appeal differ.
What is the rest of the coin made of?
The 1837 Act makes the alloy copper and silver, with the silver no more than half of it, so the remaining 3.344 g is copper, with silver making up no more than half of it.
Other coins
The same question for other popular gold coins:
- How Much Gold Is in a Gold Britannia?
- How Much Gold Is in a Gold Maple Leaf?
- How Much Gold Is in a Krugerrand?
- How Much Gold Is in a Vienna Philharmonic?
- How Much Gold Is in an American Gold Eagle?
For any coin, the content chart lists weight, fineness and sources, and the melt value calculator covers 27 coins at once.
Gold Coins Today publishes general information about coin collecting and precious metals, not financial, investment, tax or legal advice. Articles on this site are drafted with AI assistance (see our editorial policy) and are not written or reviewed by certified numismatists, appraisers, financial advisors or dealers. Coin and bullion values change constantly and depend on condition, authenticity and the current market — get a current appraisal or spot price from a qualified, reputable source before buying or selling, and consult a licensed financial advisor before treating precious metals as part of an investment strategy.