Calculate the equivalent gold price per grain from a gram, kilogram,
pennyweight or troy-ounce reference price. Select the gold purity to
estimate a purity-adjusted grain price, and optionally enter a weight to
calculate its estimated gold value. This calculator uses the grain from
the troy-weight system used for precious metals.
What Is a Grain of Gold?
A grain is a very small unit of mass within the traditional troy-weight
system. It is used as a subdivision of precious-metal weights and can be
useful when dealing with very small quantities of gold or other precious
metals.
One troy grain is approximately 0.06479891 grams. The same grain unit is
also used in the relationships between pennyweights and troy ounces.
1 troy grain = 0.06479891 grams
Because the grain is so small, prices calculated per grain can be useful
for understanding the value of small quantities, although gold is more
commonly quoted commercially per gram, kilogram or troy ounce.
How to Calculate Gold Price per Grain
If gold is quoted per gram, multiply the price per gram by the number of
grams in one troy grain.
Price per grain = Price per gram × 0.06479891
If the reference price is per pennyweight, divide it by 24 because one
pennyweight contains exactly 24 grains.
Price per grain = Price per DWT ÷ 24
If the reference is per troy ounce, divide it by 480 because one troy ounce
contains exactly 480 grains.
Price per grain = Price per troy ounce ÷ 480
One kilogram contains approximately 15,432.3584 troy grains.
Price per grain = Price per kilogram ÷ 15,432.3584
Gold Weight Conversion Reference
| Unit |
Equivalent in Grains |
| 1 grain |
1 grain |
| 1 gram |
15.4323584 grains |
| 1 pennyweight |
24 grains |
| 1 troy ounce |
480 grains |
| 1 kilogram |
15,432.3584 grains |
| 100 grains |
6.479891 g |
Gold Price per Grain by Purity
Gold purity changes the amount of pure gold represented by a particular
weight of jewellery alloy. Karat expresses the nominal gold fraction out
of 24 parts.
Purity-adjusted grain price = 24K grain price × (Karat ÷ 24)
For example, nominal 22K gold represents 22 parts gold out of 24, or
approximately 91.67%. Eighteen-karat gold represents a nominal 75% gold
fraction.
| Karat |
Nominal Gold Fraction |
Price Factor |
| 24K | 100.00% | 1.0000 |
| 23K | 95.83% | 0.9583 |
| 22K | 91.67% | 0.9167 |
| 21K | 87.50% | 0.8750 |
| 20K | 83.33% | 0.8333 |
| 18K | 75.00% | 0.7500 |
| 14K | 58.33% | 0.5833 |
| 10K | 41.67% | 0.4167 |
| 9K | 37.50% | 0.3750 |
Grain vs Pennyweight vs Troy Ounce
Grain, pennyweight and troy ounce are related units within the troy-weight
system. Understanding their exact relationships makes conversion between
precious-metal quotations straightforward.
| Unit |
Grains |
Approx. Grams |
| 1 grain |
1 |
0.06479891 g |
| 1 pennyweight |
24 |
1.55517384 g |
| 1 troy ounce |
480 |
31.1034768 g |
The grain used for precious-metal calculations belongs to the troy system.
Do not confuse it with unrelated everyday measurements or regional
historical units that may use the word "grain."
Using Grain Measurements for Small Gold Quantities
Because a grain is only about 0.0648 grams, it can describe very small
precious-metal quantities. A grain-based calculation can therefore be
useful when examining small weights or converting older precious-metal
measurements.
Estimated metal value = Purity-adjusted price per grain × Weight in grains
For normal jewellery transactions, however, grams and pennyweights are
often more convenient because they produce easier-to-read weights.
Using Grain Prices for Jewellery and Scrap Gold
A theoretical grain value can help establish the underlying metal value of
a small quantity of gold. The result should not automatically be treated
as the amount a dealer will pay.
Scrap gold
Actual scrap offers can reflect testing, refining losses, processing
costs, market spreads and the buyer's margin.
Jewellery
Finished jewellery can contain labour, design costs, gemstones,
wastage, taxes and retailer margins beyond the theoretical gold value.
Small quantities
A grain-based calculation can provide a precise unit conversion when
the quantity involved is very small.
Gold Price per Grain and Market Quotations
International gold markets generally quote gold using larger units,
particularly troy ounces. A grain price is therefore normally a derived
value rather than the primary market quotation.
Since one troy ounce equals exactly 480 grains, any troy-ounce quotation
can be converted directly into a price per grain.
1 troy ounce = 480 grains
This makes grain useful as a mathematical subdivision of the troy-ounce
price, especially when working with very small quantities.
Important Limitations
This calculator does not retrieve or guarantee a live gold market price.
The result depends on the reference price entered by the user.
The purity calculation is a theoretical karat-based estimate. It does not
assay, authenticate or test physical gold.
Actual gold buying and selling prices may differ because of dealer spreads,
refining costs, premiums, taxes, workmanship, stones and other commercial
factors.
The calculator uses the standard troy grain of approximately 0.06479891
grams. Commercial transactions should use the applicable weight and
pricing standards of the relevant market.
Frequently Asked Questions
How many grams are in one grain of gold?
One troy grain equals approximately 0.06479891 grams.
How many grains are in one pennyweight?
One pennyweight contains exactly 24 grains.
How many grains are in one troy ounce?
One troy ounce contains exactly 480 grains.
How do I calculate gold price per grain from price per gram?
Multiply the price per gram by approximately 0.06479891.
How do I calculate gold price per grain from a troy-ounce price?
Divide the troy-ounce price by 480.
Does gold purity affect price per grain?
Yes. A purity-adjusted calculation depends on the selected karat's nominal
gold fraction.
Is this a live gold price calculator?
No. It calculates from the reference price entered by the user and does not
guarantee a live market quotation.
Can I calculate a small gold item's value in grains?
Yes. Enter the reference price, select the purity and enter the item's weight
in grains, grams, pennyweights, troy ounces or kilograms.