Calculate the equivalent gold price per pennyweight, commonly abbreviated
as DWT, from a gram, kilogram or troy-ounce reference price. Select the
gold purity to estimate a purity-adjusted pennyweight price, and optionally
enter a gold weight to estimate its value. Pennyweight is a traditional
precious-metal unit still used in parts of the jewellery and bullion trade.
What Is a Pennyweight?
A pennyweight is a traditional unit of mass used in precious-metal work.
It is commonly abbreviated as dwt and remains familiar
among jewellery professionals, gold dealers and some refiners.
One pennyweight equals 24 grains and is approximately 1.55517384 grams.
The unit is part of the troy-weight system used for precious metals.
1 DWT = 1.55517384 grams
Pennyweight should not be confused with an ordinary ounce. Twenty
pennyweights make one troy ounce, so the relationship is particularly
convenient for precious-metal calculations.
How to Calculate Gold Price per Pennyweight
If a gold price is quoted per gram, multiply the gram price by the number
of grams in one pennyweight.
Price per DWT = Price per gram × 1.55517384
If a quotation is already given per troy ounce, divide it by 20 because
one troy ounce contains 20 pennyweights.
Price per DWT = Price per troy ounce ÷ 20
When a reference price is quoted per kilogram, one kilogram contains
approximately 643.014931 DWT.
Price per DWT = Price per kilogram ÷ 643.014931
If the reference is already expressed per pennyweight, the calculator can
use it directly before applying the selected purity adjustment.
Pennyweight Gold Conversion Reference
| Unit |
Equivalent Weight |
| 1 pennyweight |
1.55517384 g |
| 1 gram |
0.6430149 DWT |
| 1 troy ounce |
20 DWT |
| 1 kilogram |
643.0149 DWT |
| 10 DWT |
15.5517384 g |
| 20 DWT |
31.1034768 g |
Gold Price per Pennyweight by Purity
A gold price reference normally needs a purity basis before it can be
applied to jewellery alloys. Karat expresses the nominal proportion of
gold out of 24 parts.
Purity-adjusted DWT price = 24K DWT price × (Karat ÷ 24)
For example, nominal 22K gold contains 22 parts gold out of 24, giving a
theoretical gold fraction of approximately 91.67%. Eighteen-karat gold
has a nominal fraction of 75%.
| 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 |
Pennyweight vs Gram vs Troy Ounce
These units describe different quantities of mass. Using the correct
conversion is essential when comparing gold prices from different sources.
| Unit |
Weight |
Relationship to DWT |
| 1 gram |
1 g |
0.6430149 DWT |
| 1 pennyweight |
1.55517384 g |
1 DWT |
| 1 troy ounce |
31.1034768 g |
20 DWT |
| 1 kilogram |
1,000 g |
643.0149 DWT |
A pennyweight belongs to the troy-weight system. Do not substitute an
ordinary avoirdupois ounce when converting precious-metal weights.
Using Pennyweight for Gold Jewellery
Pennyweight is particularly useful when working with jewellery because
traditional jewellery scales and trade references may use DWT. Once the
gold price per DWT and the item's weight are known, the underlying
theoretical metal value can be estimated.
Estimated metal value = Purity-adjusted DWT price × Weight in DWT
This calculation describes the metal component only. A finished jewellery
price can include labour, design, stones, wastage, taxes, retailer margins
and other commercial costs.
How Jewelers Use Pennyweight
Pennyweight has a long association with jewellery and precious-metal
measurement. In settings where DWT is still used, a jeweller may record
an item's weight in pennyweights and calculate the metal value using a
price per DWT.
Metal valuation
A DWT-based gold price can provide a convenient way to estimate the
underlying value of a known jewellery weight.
Scrap calculations
Scrap buyers can use weight and purity as inputs when estimating
recoverable gold content. Actual offers can differ because of refining
costs, testing, spreads and buyer margins.
Jewellery pricing
Retail jewellery pricing requires more than the DWT metal value.
Workmanship, design, stones, taxes and commercial margins may all be
added separately.
Gold Price per DWT vs Gold Price per Troy Ounce
Because one troy ounce contains exactly 20 pennyweights, the two quotations
can be converted directly.
1 troy ounce = 20 pennyweights
Therefore, a gold price of 3,000 per troy ounce would correspond to
150 per DWT before any purity adjustment, assuming both prices use the
same currency and market basis.
This relationship makes pennyweight useful for translating international
bullion quotations into a unit familiar to jewellery professionals.
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 jewellery or scrap-buying prices can differ substantially from the
calculated metal value because of workmanship, stones, refining costs,
dealer spreads, taxes, premiums and other commercial factors.
The calculator uses the standard DWT conversion of approximately
1.55517384 grams per pennyweight. Commercial transactions should use the
applicable weight and pricing standards of the relevant market.
Frequently Asked Questions
How many grams are in one pennyweight of gold?
One pennyweight equals approximately 1.55517384 grams.
What does DWT mean in gold?
DWT is the common abbreviation for pennyweight, a traditional precious-metal
weight unit.
How do I calculate gold price per pennyweight from price per gram?
Multiply the price per gram by approximately 1.55517384.
How many pennyweights are in one troy ounce?
One troy ounce contains exactly 20 pennyweights.
Is a pennyweight the same as an ordinary ounce?
No. Pennyweight is a much smaller unit. One pennyweight is approximately
1.55517384 grams, while an ordinary ounce is approximately 28.35 grams.
Does gold purity affect the price per DWT?
Yes. A purity-adjusted calculation changes according to 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 jewellery value in pennyweight?
Yes. Enter the reference price, select the purity and enter the jewellery
weight in DWT, grams, troy ounces or kilograms.