Mixed-Karat Gold Lot Calculator
Add every item in a lot — several rings, an old chain, a bracelet — each at its own karat, and see the total fine-gold weight and melt value in one place. Built for US jewellers, gold buyers and consumers sorting a mixed lot before selling.
Mixed-Karat Lot Calculator
UnavailableChecking the platform reference…Add every item in the lot with its own weight and karat, and see the total fine-gold content and melt value — using the platform's reference Gold price or a price you enter yourself.
Checking the platform reference price… Item weights and fine-gold totals are still shown below — switch to Manual price to enter your own and see a melt value.
Lot items
- Item 1
0 of 1 item included in the totals below — 1 row has an empty or invalid weight and does not contribute.
Enter a weight for at least one item to see the lot fine-gold weight and melt value.
How this is calculated
Each item's fine gold weight = its gross weight × its own purity fraction (14K = 14/24, and so on) — the same arithmetic the Scrap Gold / Melt Value calculator uses, once per item.
Weighted lot purity = total fine-gold weight ÷ total gross weight — never the arithmetic average of the karat numbers themselves. A 10g 14K item plus a 5g 18K item is not "16K": it is weighted toward whichever item weighs more. Equivalent lot karat is that weighted purity expressed on the familiar 24-point scale.
Melt value is the reference value of the gold content only — each item's fine weight multiplied by the same Gold price, summed across the lot. It is not a buyer offer, a retail price, or an appraisal.
What a mixed-karat lot is
A mixed-karat lot is a group of Gold items — rings, chains, bracelets, broken pieces — that are not all the same purity. This is the everyday reality of an estate, an inheritance, or a drawer of old jewellery: a 14K chain sits next to an 18K ring and a 10K class ring, and none of them is worth the same amount of Gold per gram.
Why weights cannot simply be added across karats
Adding a 10g 14K item and a 5g 18K item as "15 grams of Gold" would overstate the fine-gold content — 14K is 14/24 fine and 18K is 18/24 fine, so each gram of the two items contains a different amount of pure Gold. Each item's fine-gold weight must be worked out on its own karat first, and only the FINE weights — never the gross weights — can be meaningfully summed.
Weighted lot purity
The lot's weighted purity is total fine-gold weight ÷ total gross weight — never the arithmetic average of the karat numbers themselves. A small 18K item does not pull a large 10K item's average up to a simple midpoint; the heavier item counts for more. The equivalent lot karat is that same weighted purity expressed on the familiar 24-point scale — it describes the lot as a whole, not any single item in it.
Worked example
A 10 gram 14K item plus a 5 gram 18K item, at a Gold price of $65 per gram:
- Total gross weight: 15.0000 g
- Total fine-gold weight: 9.5833 g
- Weighted lot purity: 63.89% fine
- Equivalent lot karat: 15.33K
- Melt value: $622.92
What melt value is not
Melt value is the reference value of the gold content only. It is not a buyer offer (what a specific buyer proposes to pay, usually below melt value), not a retail selling price (which adds making charge, markup and other costs), and not an appraisal or collectible value (which can reflect brand, craftsmanship, age or rarity that has nothing to do with the gold content). This calculator values the gold in the lot only — nothing else, and it does not add tax, a making charge, or a buyer deduction.
Common US mixed-lot scenarios
Several pieces bought at different times and karats, an old jewellery box sorted for the first time in years, inheritance or estate Gold with no paperwork on purity, or a jeweller or refiner sorting intake before a scrap run — a mixed lot is the normal case, not the exception. This tool does not make any claim about how a particular dealer or refiner will price a lot in practice.