Convert gold prices between grams, kilograms, troy ounces, tola,
pennyweight and grains. The converter also lets you change the assumed
gold purity, so a quoted 24K, 22K, 18K or other reference can be converted
into an equivalent price for another purity. You can optionally enter a
physical gold weight to estimate its theoretical metal value.
What Does a Gold Price Unit Converter Do?
Gold can be quoted using several different weight units. International
bullion markets commonly use troy ounces, while grams and kilograms are
widely used for physical gold. Traditional units such as tola and
pennyweight also remain relevant in particular markets and jewellery
settings.
A unit converter makes these quotations directly comparable. Instead of
manually converting the same reference repeatedly, this tool calculates
the equivalent price across all supported units in one result.
The converter also separates weight conversion from purity conversion.
That distinction matters when the source quotation is for one karat but
the desired comparison is for another.
How the Gold Price Conversion Works
Step 1: Convert the source price to price per gram
Every supported unit has a known relationship with grams. The reference
price is first converted to an equivalent price per gram.
Pure-gold reference price per gram = Source price ÷ source-unit grams × source-purity adjustment
Step 2: Remove the source purity effect
If the source quotation is for 22K rather than 24K, the converter derives
the theoretical pure-gold reference before applying the new target purity.
Pure-gold price per gram = Source price per gram ÷ (Source karat ÷ 24)
Step 3: Apply the target purity
The theoretical pure-gold price is then multiplied by the target karat
fraction.
Target price per gram = Pure-gold price per gram × (Target karat ÷ 24)
Step 4: Convert to the target unit
Finally, the target price per gram is multiplied by the number of grams
contained in the selected target unit.
Gold Weight Units Supported
| Unit |
Approximate Weight in Grams |
Relationship |
| Gram |
1 g |
1 gram |
| Kilogram |
1,000 g |
1,000 grams |
| Troy Ounce |
31.1034768 g |
20 DWT |
| Tola |
11.6638125 g |
180 grains |
| Pennyweight |
1.55517384 g |
24 grains |
| Grain |
0.06479891 g |
1 grain |
The tola value used here follows the modern bullion convention. Historical
or regional definitions can differ, so a specific commercial transaction
should use the convention agreed by the relevant market.
Gold Purity Conversion
Karat expresses the nominal proportion of gold out of 24 parts. A 24K
reference therefore has a nominal fraction of 24/24, while 22K has
22/24 and 18K has 18/24.
| Karat |
Nominal Gold Fraction |
Fineness Equivalent |
| 24K | 100.00% | 1,000 |
| 23K | 95.83% | 958.3 |
| 22K | 91.67% | 916.7 |
| 21K | 87.50% | 875 |
| 20K | 83.33% | 833.3 |
| 18K | 75.00% | 750 |
| 14K | 58.33% | 583.3 |
| 10K | 41.67% | 416.7 |
| 9K | 37.50% | 375 |
Why Purity Matters When Converting Gold Prices
A weight conversion alone does not tell you the equivalent price of a
lower-karat alloy. For example, converting a price from dollars per gram
to dollars per troy ounce changes only the weight unit. Converting from
24K to 18K also changes the theoretical amount of pure gold represented
by that price.
Same purity, different unit
A 24K price per gram converted to troy ounces is simply a unit
conversion. The gold purity remains the same.
Different purity, same unit
A 24K price per gram converted to an 18K price per gram requires a
purity adjustment in addition to any unit conversion.
Different purity and unit
This is where a multi-purpose converter is most useful: it handles the
purity adjustment first and the weight-unit conversion consistently.
Example: Converting a Gold Price
Suppose a reference quotation is entered as 3,000 per troy ounce at 24K,
and the target is 22K per gram.
The calculator first converts the troy-ounce quotation into a price per
gram, then applies the 22/24 purity factor. The result is therefore a
theoretical 22K price per gram derived from the original 24K quotation.
22K target price = 24K reference price × (22 ÷ 24) after weight-unit conversion
The same underlying calculation can then be displayed per kilogram, tola,
pennyweight or grain without changing the assumed gold value.
Using the Converter for Gold Jewellery
The converter can be used as a reference when comparing jewellery quoted
by different weight units or purities. For example, a quotation expressed
in price per gram can be translated into pennyweight or troy-ounce terms
for comparison with another source.
However, the converted metal price should not be mistaken for the final
price of finished jewellery. Labour, design, stones, wastage, taxes,
retailer margins and brand premiums can all add to the transaction price.
Using the Converter for Bullion
Bullion traders and buyers may encounter quotations in troy ounces,
kilograms or grams depending on the market and product. Converting them
into a common unit makes comparisons easier.
Physical bars and coins can still trade at a premium or discount relative
to a theoretical metal price. Product size, refinery, mint, availability,
distribution costs and dealer spreads can affect the actual transaction
price.
Important Limitations
This calculator does not retrieve or guarantee a live gold market
quotation. The result depends on the reference price entered by the user.
The purity calculation is a nominal karat-based mathematical conversion.
It does not assay or verify the composition of physical gold.
The tola conversion uses 11.6638125 grams per tola, reflecting the modern
bullion convention. Historical and regional definitions can differ.
Actual buying, selling, jewellery and bullion prices may differ from the
calculated value because of premiums, discounts, making charges, taxes,
dealer spreads, refining costs and other commercial factors.
Frequently Asked Questions
What gold price units can this converter handle?
It converts between grams, kilograms, troy ounces, tola, pennyweight and
grains.
Can I convert a 24K price into a 22K price?
Yes. Select the original reference purity and then select 22K as the target
purity. The calculator adjusts the theoretical gold content.
How many grams are in one troy ounce?
One troy ounce is approximately 31.1034768 grams.
How many grams are in one tola?
This converter uses approximately 11.6638125 grams per modern bullion tola.
How many grams are in one pennyweight?
One pennyweight is approximately 1.55517384 grams.
How many grams are in one grain?
One troy grain is approximately 0.06479891 grams.
Does the converter provide a live gold price?
No. It converts the reference price that you enter and does not guarantee a
live market quotation.
Is the converted price the same as a jewellery shop price?
No. Jewellery can include making charges, stones, taxes, wastage, retailer
margins and other costs beyond the underlying gold value.