What this calculator does
This gold weight calculator turns a volume into a weight using density, the same relationship used for any material: weight = volume × density. Pure gold has a fixed, well-known density of 19,320 kg per cubic metre, but most gold jewellery and bars are an alloy, so the density used here changes with the karat purity selected, from 24k down to 9k, and can be typed in directly for anything in between.
Karat purity matters because gold is almost always alloyed with other metals, usually silver, copper or zinc, to make it hard-wearing enough for jewellery. Lower-karat gold contains a larger share of these lighter alloy metals, so it is measurably less dense than pure 24k gold of the same volume, and a gold chain weight calculator that assumes pure gold will overstate the weight of an 18k or 9k piece.
The formula
The karat selector sets a typical density for that purity, based on common alloy compositions: 24k at 19,320 kg/m³ down to 9k at 11,000 kg/m³. Selecting Custom switches to a density you enter directly, useful for a specific manufacturer figure or a non-standard alloy. Weight is then just volume × density, converted into grams, kilograms, troy ounces (the unit used for precious metal weights) and ordinary avoirdupois ounces.
| Term | Meaning |
|---|---|
| Karat (k) | A measure of gold purity out of 24 parts. 24k is essentially pure gold; 18k is 18 parts gold to 6 parts other metal, or 75% pure. |
| Density | Mass per unit volume. Pure gold is 19,320 kg/m³; alloying with lighter metals lowers this figure. |
| Troy ounce | The traditional unit for weighing precious metals, equal to 31.1034768 g, and about 10% heavier than an ordinary avoirdupois ounce. |
The inputs explained
| Field | What to enter |
|---|---|
| Gold purity | The purity of the gold. Choose a standard karat for a typical density, or Custom to enter your own figure. |
| Custom density (custom purity only) (kg/m³) | Only used when Custom is selected above. Enter the density of your specific alloy in kg/m³. |
| Volume of the item (cm³) | The volume of the gold item. For an irregular shape like a piece of jewellery, this usually comes from a water-displacement measurement or a supplier specification. |
When to use it
Estimating the weight of a gold chain
A gold chain weight calculator is most useful when only a volume or dimensions are known, such as from a mould or a jeweller's spec sheet, and the karat stamped on the clasp gives the purity to use.
Comparing what different karats weigh for the same design
A ring or bangle cast in the same mould weighs less in 9k than in 18k, purely because the alloy is less dense, which matters when pricing a design across multiple purities.
Working with a known manufacturer density
Some refiners and casters quote an exact alloy density rather than a generic karat figure. Selecting Custom and entering that number gives a more precise weight of gold than the standard karat table.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How much does 10 cm³ of gold weigh at each karat?
The same volume weighs noticeably less as the karat purity drops, because the density of the alloy falls.
| Karat | Weight | Weight in troy ounces |
|---|---|---|
| 24k | 193.20 g | 6.212 oz t |
| 22k | 177.00 g | 5.691 oz t |
| 18k | 152.00 g | 4.887 oz t |
| 14k | 131.00 g | 4.212 oz t |
| 9k | 110.00 g | 3.537 oz t |
Weight of gold by volume at 18k
Weight scales directly with volume once the density is fixed, so doubling the volume doubles the weight.
| Volume | Weight | Weight in kilograms |
|---|---|---|
| 1 cm³ | 15.20 g | 0.0152 kg |
| 5 cm³ | 76.00 g | 0.0760 kg |
| 10 cm³ | 152.00 g | 0.1520 kg |
| 20 cm³ | 304.00 g | 0.3040 kg |
| 50 cm³ | 760.00 g | 0.7600 kg |
Questions
How do you calculate the weight of gold?
Weight = volume × density. Pure gold has a density of 19,320 kg/m³ (19.32 g/cm³); alloyed gold at a lower karat is less dense, so the same volume weighs less.
Does karat affect the weight of gold?
Yes. Karat measures purity out of 24, and the alloy metals mixed in to make lower-karat gold, usually silver, copper or zinc, are less dense than gold itself, so a lower-karat item of the same volume weighs less.
What is the density used for each karat?
This calculator uses approximate typical figures: 19,320 kg/m³ for 24k, 17,700 for 22k, 15,200 for 18k, 13,100 for 14k and 11,000 for 9k. Exact alloy densities vary by manufacturer, which is what the Custom option is for.
Why measure gold weight in troy ounces?
Troy ounces are the traditional unit for weighing precious metals and gemstones, and are about 10% heavier than the everyday avoirdupois ounce used for most other goods. Gold prices are almost always quoted per troy ounce.
For the weight of other solid materials from their dimensions, see the steel plate weight calculator. To convert the resulting weight between units, see the pounds to kilos calculator.