Convert a gold coin's weight between grams, kilograms, troy ounces,
pennyweight, tola and grains. Use common coin-size presets or enter any
measured or stated coin weight to compare the equivalent mass.
How Gold Coin Weight Conversion Works
Gold coins are produced in many different sizes and may be described using
grams or troy ounces depending on the product and market. This converter
lets you translate a coin's stated or measured mass into other commonly
encountered precious-metal weight units.
The calculation begins by converting the entered mass into grams. The
result is then converted into kilograms, troy ounces, pennyweight, tola
and grains.
1 troy ounce = 31.1034768 grams
1 kilogram = 1,000 grams
1 pennyweight = 1.55517384 grams
1 tola = 11.6638125 grams
1 grain = 0.06479891 grams
Common Gold Coin Weights
Many bullion coins are specified by fractional troy-ounce weights. The
following table converts those nominal weights into grams.
| Nominal Coin Weight |
Grams |
Kilograms |
| 1/20 troy oz |
1.55517384 g |
0.001555174 kg |
| 1/10 troy oz |
3.11034768 g |
0.003110348 kg |
| 1/4 troy oz |
7.77586920 g |
0.007775869 kg |
| 1/2 troy oz |
15.55173840 g |
0.015551738 kg |
| 1 troy oz |
31.10347680 g |
0.031103477 kg |
| 2 troy oz |
62.20695360 g |
0.062206954 kg |
| 5 troy oz |
155.51738400 g |
0.155517384 kg |
| 10 troy oz |
311.03476800 g |
0.311034768 kg |
Fractional Gold Coin Weights
Fractional bullion coins are often described as fractions of a troy ounce.
This makes it useful to know the exact metric equivalent when comparing
products or checking specifications.
One-Tenth Troy Ounce
One-tenth of a troy ounce is 3.11034768 grams.
31.1034768 ÷ 10 = 3.11034768 g
One-Quarter Troy Ounce
One-quarter troy ounce is 7.7758692 grams.
One-Half Troy Ounce
One-half troy ounce is 15.5517384 grams.
One Troy Ounce
One troy ounce is exactly 31.1034768 grams.
Coin Weight and Fine Gold Content
A gold coin's gross weight does not necessarily equal the mass of pure
gold inside it. Some coins are made from high-purity gold while others use
an alloy containing additional metals.
Fine-gold content can be estimated from gross weight and fineness when the
relevant specifications are known.
Fine Gold Content = Gross Weight × Fineness
For example, a 31.1034768 gram coin with a fineness of 0.999 contains
approximately 31.0723733 grams of fine gold.
Gross weight and fine-gold weight are
different measurements and should not be treated as interchangeable.
Gold Coin Weight Does Not Prove Authenticity
Weight is one useful specification when examining a gold coin, but it is
not by itself an authentication test. Genuine coins can have published
tolerances, and counterfeit pieces may sometimes be manufactured to match
an expected weight.
Authentication can require additional checks such as dimensions,
specific gravity, magnetism, professional testing or examination by a
qualified specialist, depending on the coin and circumstances.
Gold Coin Weight and Market Value
A coin's weight is an important part of understanding its gold content, but
weight alone does not establish its market value.
Bullion value can depend on fine-gold content and the current gold market
price. Collectible coins can also have premiums influenced by rarity,
condition, demand, issue details and other numismatic factors.
Gross weight
The total physical mass of the coin.
Fine-gold content
The amount of pure gold represented by the coin's mass and fineness.
Market value
The price at which a coin can actually be bought or sold, which may be
different from its melt value.
Troy Ounce Versus Regular Ounce
Gold coins described in ounces normally use the troy-ounce system. A troy
ounce is different from the avoirdupois ounce used for many everyday goods.
| Unit |
Mass |
Typical Use |
| Troy ounce |
31.1034768 g |
Precious metals |
| Avoirdupois ounce |
28.349523125 g |
General goods |
When comparing gold coin specifications, make sure an ounce-based weight
refers to a troy ounce.
Using a Scale With Gold Coins
If you are checking a physical coin, use a sufficiently precise scale and
record the measurement in the same unit used by the published
specification. Converting the measurement afterward makes comparison
easier.
A difference between a measured weight and a published nominal weight does
not automatically prove that a coin is counterfeit. Manufacturing
tolerances, scale accuracy, dirt, wear and measurement conditions can all
affect the reading.
Important Limitations
This calculator converts gold coin mass between weight units. It does not
verify authenticity, determine exact fineness, identify a particular coin
or provide a live market valuation.
Common fractional-ounce weights shown on this page are mathematical
conversions of the stated troy-ounce weights. Individual coin products may
have different gross weights because of alloy composition and product
specifications.
Frequently Asked Questions
What units can this gold coin weight converter use?
It supports grams, kilograms, troy ounces, pennyweight, tola and grains.
How much does a 1 troy ounce gold coin weigh?
A coin with a gross weight of exactly 1 troy ounce has a mass of
31.1034768 grams.
Is a gold coin's total weight the same as its fine gold content?
Not necessarily. A coin can contain an alloy, so its gross weight and fine
gold content can differ.
How much does a 1/2 troy ounce gold coin weigh in grams?
One-half troy ounce equals 15.5517384 grams.
How much does a 1/4 troy ounce gold coin weigh?
One-quarter troy ounce equals 7.7758692 grams.
How much does a 1/10 troy ounce gold coin weigh?
One-tenth troy ounce equals 3.11034768 grams.
Does gold purity affect coin weight conversion?
No. Gross mass conversion does not depend on purity. Purity matters separately
when determining fine-gold content.
Does this converter determine the value of a gold coin?
No. It converts weight only. Coin value can also depend on gold content, market
price, premiums, condition, rarity and other factors.