Convert a gold bar's weight between grams, kilograms, troy ounces,
pennyweight, tola and grains. You can also start with a common bullion bar
size to quickly see its equivalent weight in other units.
How to Convert Gold Bar Weight
Gold bars are manufactured and traded in many different weights. Metric
weights such as grams and kilograms are commonly used to describe physical
bullion, while troy ounces are the standard precious-metal ounce used in
international gold markets.
This converter first converts the entered bar weight into grams and then
calculates the equivalent mass in the other supported units.
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 Bar Weights
Gold bars are available in a wide range of sizes. The following weights
are useful reference points when comparing bullion products. Actual product
availability, dimensions and specifications vary by refiner and market.
| Bar Weight |
Grams |
Troy Ounces |
| 1 gram |
1 g |
≈ 0.03215075 oz t |
| 2.5 grams |
2.5 g |
≈ 0.08037687 oz t |
| 5 grams |
5 g |
≈ 0.16075373 oz t |
| 10 grams |
10 g |
≈ 0.32150747 oz t |
| 20 grams |
20 g |
≈ 0.64301493 oz t |
| 1 troy ounce |
31.1034768 g |
1 oz t |
| 50 grams |
50 g |
≈ 1.60753733 oz t |
| 100 grams |
100 g |
≈ 3.21507466 oz t |
| 250 grams |
250 g |
≈ 8.03768664 oz t |
| 500 grams |
500 g |
≈ 16.07537328 oz t |
| 1 kilogram |
1,000 g |
≈ 32.15074657 oz t |
| 400 troy ounces |
≈ 12,441.401 g |
400 oz t |
Small Gold Bars
Small bars are often described directly in grams. Common sizes include
1 gram, 2.5 grams, 5 grams, 10 grams, 20 grams and 50 grams. Gram-based
specifications make these products easy to compare with metric scales and
other gold weights.
A 10 gram bar, for example, contains a gross mass of 10 grams. That is
approximately 0.32150747 troy ounces.
10 g ÷ 31.1034768 ≈ 0.32150747 troy oz
The same 10 gram bar is approximately 6.43015 pennyweights, 0.857348 tola
and 154.32358 grains.
100 Gram Gold Bar
The 100 gram gold bar is a useful reference size because its metric weight
is straightforward while its equivalent troy-ounce weight demonstrates the
difference between metric and precious-metal units.
100 grams ≈ 3.21507466 troy ounces
In other units, the same mass is approximately 0.1 kilogram, 64.3015
pennyweights, 8.57353 tola or 1,543.23583 grains.
1 Kilogram Gold Bar
A 1 kilogram gold bar has a gross mass of exactly 1,000 grams. When
expressed in the troy-ounce system, that mass is approximately
32.15074657 troy ounces.
1,000 g ÷ 31.1034768 ≈ 32.15074657 troy oz
A kilogram bar is therefore not the same weight as a 32 troy ounce bar,
although the two are very close. Thirty-two troy ounces equal
approximately 995.2 grams.
400 Troy Ounce Gold Bar
The 400 troy ounce format is associated with large institutional bullion
markets. Its nominal mass is approximately 12.441 kilograms.
400 × 31.1034768 g = 12,441.39072 g
= 12.44139072 kg
Actual large bullion bars can have individual weights and markings that
differ from the nominal target, so the specific bar's stated or measured
weight should always be checked.
Gold Bar Weight and Purity
A gold bar's gross weight and gold purity are separate characteristics.
A bar can contain a specified mass of alloy while having a fineness below
pure gold.
For example, if a bar weighs 100 grams and has a fineness of 999.9, its
fine-gold content is approximately 99.99 grams.
Fine Gold Content = Gross Weight × Fineness
This distinction matters when comparing the actual gold content or value
of bars with different purities.
Gold Bar Weight Versus Gold Bar Value
Weight alone does not determine the purchase or resale price of a gold
bar. A valuation can depend on the current gold market price, bar purity,
dealer premium, manufacturing costs, market conditions and transaction
terms.
The converter on this page deliberately focuses on weight. It does not
assume a gold price or attempt to estimate a bar's current market value.
Weight
Describes how much the bar weighs.
Purity
Describes the proportion of the bar that is fine gold.
Value
Depends on gold content and the applicable market or transaction price.
Troy Ounce Versus Regular Ounce
Gold bars should generally be discussed in troy ounces when an ounce-based
precious-metal measurement is intended. A troy ounce is heavier than the
ordinary avoirdupois ounce used for many everyday products.
| Unit |
Mass |
Use |
| Troy ounce |
31.1034768 g |
Precious metals |
| Avoirdupois ounce |
28.349523125 g |
General goods |
Important Limitations
This tool converts mass and provides reference comparisons for gold bar
weights. It does not verify a bar's authenticity, assay, dimensions,
serial number, refinery, purity or market value.
Listed common bar sizes are reference weights rather than a guarantee that
every refiner or dealer offers every size.
For a physical gold transaction, use the manufacturer's documentation,
assay information and an appropriate verified scale where necessary.
Frequently Asked Questions
What units can this gold bar weight converter use?
It supports grams, kilograms, troy ounces, pennyweight, tola and grains.
How much does a 1 kilogram gold bar weigh in troy ounces?
A 1 kilogram gold bar is approximately 32.1507465686 troy ounces.
How much does a 100 gram gold bar weigh in troy ounces?
A 100 gram gold bar is approximately 3.2150746569 troy ounces.
How much does a 10 gram gold bar weigh in troy ounces?
A 10 gram gold bar is approximately 0.3215074657 troy ounces.
Does gold purity change a gold bar's weight?
No. Purity does not change gross mass. It changes the amount of fine gold
contained within that mass.
How many grams are in a troy ounce of gold?
One troy ounce equals exactly 31.1034768 grams.
What is the largest common gold bar size?
The 400 troy ounce format is a major institutional bullion format and has a
nominal mass of approximately 12.441 kilograms.
Does this calculator determine the value of a gold bar?
No. It converts weight only. Value requires a relevant gold price, purity and
other applicable costs or premiums.