Pennyweight
Also: dwt, DWT, Penny Weight
The pennyweight (dwt) is a unit of weight within the troy system equal to 1/20 of a troy ounce, used primarily in Anglo-American jewellery and goldsmithing trades.
The pennyweight (abbreviation: dwt) is a unit of weight from the troy weight system, which has been used since the Middle Ages for weighing precious metals and coins. The name derives from the English penny: in medieval England, a silver penny coin weighed exactly one pennyweight. The abbreviation dwt comes from the Latin denarius weight — the denarius was the Roman predecessor of the penny.
Conversions at a Glance
| Unit | Value in dwt |
|---|---|
| 1 Pennyweight (dwt) | 1 dwt |
| 1 Troy Ounce (ozt) | 20 dwt |
| 1 Troy Pound | 240 dwt |
| 1 Grain | 1/24 dwt |
In metric units:
1 dwt = 24 grains = 1/20 troy ounce ≈ 1.55517 grams
For comparison: the avoirdupois ounce (the common ounce for everyday goods) equals approximately 18.23 dwt — it is therefore lighter than a troy ounce (20 dwt).
Use in Practice and Trade
In German-speaking countries the pennyweight plays virtually no role; grams and the troy ounce are the standard units there. The Anglo-American market is different: goldsmiths, jewellers, and pawnshops in the USA, Canada, and Australia regularly quote scrap gold buying prices in dwt. Anyone selling scrap gold or jewellery there will therefore encounter the pennyweight frequently in buying offers and price lists.
Typical use cases:
- Valuation of scrap gold and jewellery at point of purchase
- Weight specifications in US coin catalogues and auction catalogues
- Dental gold valuation (particularly in the North American market)
The spot price per dwt is calculated simply as:
Price/dwt = Spot Price (USD/ozt) ÷ 20
Current conversions and the melt value of scrap gold in dwt can be quickly determined using the unit converter or the melt value calculator.
Distinction from Similar Units
The pennyweight is exclusively part of the troy system and must not be confused with the avoirdupois system, which applies to everyday goods. Other regionally used small units such as the tola (South Asian region, ≈ 11.66 g = 7.5 dwt) or the tael (East Asian region) are not compatible with the pennyweight system.
Key Takeaway
One pennyweight equals exactly 1.55517 grams, or 1/20 of a troy ounce, and is the most common small unit in the Anglo-American jewellery and scrap gold trade — anyone comparing offers there should keep the simple formula "÷ 20 = troy ounces" handy.