Gold Weight Converter.
Convert a weight between grams, troy ounces, pennyweight, tola, carats and grains — every unit a jeweler meets, in one place.
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| Unit | Weight |
|---|---|
| Grams (g)The everyday unit at the bench and on most invoices. | 31.10348 |
| Pennyweight (dwt)One twentieth of a troy ounce; common in US casting and repair. | 20 |
| Tola180 grains, about 11.66 g; used for gold in South Asia and the Gulf. | 2.66667 |
| Carats (ct)Gemstone weight: 0.2 g. Not the same thing as karat. | 155.51738 |
| Grains (gr)The unit the troy and tola systems are defined from. | 480 |
| Ounces, Avoirdupois (oz)The kitchen and postage ounce. Not used for precious metal. | 1.09714 |
| Kilograms (kg)Bullion and bulk metal. | 0.0311 |
Troy Ounces Are Not Ordinary Ounces
Precious metal is weighed in troy ounces of 31.1035 g, about 10% heavier than the 28.3495 g avoirdupois ounce on a kitchen scale. Confusing the two understates gold by roughly a tenth.
The Units Jewelers Use
Different parts of the trade weigh in different units, so the same piece can be described three ways on one day.
- Gram — the bench and most supplier invoices
- Troy ounce — spot prices and bullion
- Pennyweight (dwt) — 1/20 troy ounce, common in US casting and repair
- Tola — 11.6638 g, the gold unit across South Asia and the Gulf
- Carat — 0.2 g, for gemstones; not karat, which is gold purity
Exact Conversion Factors
1 troy ounce = 31.1034768 g = 20 pennyweight = 480 grains. 1 pennyweight = 1.55517384 g. 1 grain = 64.79891 mg. 1 tola = 180 grains ≈ 11.6638 g. 1 carat = 0.2 g.
Weights From Every Supplier, In One Place
When a supplier's invoice arrives, Mero reads it as it is, matches each line to your purchase order, and fills in each piece's karat, diamond and color-stone carats, and metal and labor cost in your currency — no retyping by hand.
Common Questions.
- How many grams are in a troy ounce?
- 31.1034768 grams.
- How many grams are in a pennyweight?
- 1.55517384 grams. There are 20 pennyweight in a troy ounce.
- How many grams are in a tola?
- About 11.6638 grams. A tola is defined as 180 grains.
- Is a carat the same as a karat?
- No. A carat (ct) is a unit of gemstone weight, 0.2 g. Karat (K) measures gold purity in parts of 24.
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