18ct gold per gram: what scrap gold is worth today and how to value your items

Understanding 18ct gold per gram values requires knowledge of purity standards, market spot prices, and how refining margins impact payouts. This guide explores the calculation process, hallmark identification, and how to assess offers objectively.

Key facts

  • The value of 18ct gold is based on its 75% pure gold content, with the remainder being alloyed metals 1 2.
  • Gold scrap buyers typically offer 70% to 90% of the theoretical melt value to cover refining, testing, and operational costs 1 2.
  • The London Bullion Market Association (LBMA) sets the daily benchmark price that serves as the foundation for all UK gold trading 3 4.
  • Sellers are legally required to provide identification when selling scrap precious metals in the UK to help prevent the trade of stolen items.

When assessing the value of precious metals, understanding the distinction between market spot prices and actual scrap payouts is essential. Gold is a globally traded commodity, and its price shifts throughout the business day based on international market activity 3 5. In the UK, the value of an item is primarily determined by its gold content, often referred to as its melt value, which is the current market price multiplied by the weight and purity of the gold 5 1.

Understanding 18ct Gold Composition

Gold purity is measured in carats (ct), which indicate the proportion of pure gold within an alloy. 18ct gold contains 75% pure gold, meaning 750 parts out of every 1,000 are pure gold, with the remaining 25% consisting of metals like copper, silver, or zinc 1 4. This differentiates it from 24ct gold, which is considered near-pure at 99.9% gold content 1. The inclusion of other metals increases the durability of 18ct gold, making it a popular choice for fine jewellery, but it also means the metal must be refined to separate the gold before it can be sold as pure bullion 5 1.

To verify the purity of an item, one should look for a hallmark. In the UK, these are official marks applied by assay offices that confirm the metal's content 5. For 18ct gold, the hallmark is typically stamped as '750' 2 4. Identifying these marks is a critical first step, as buyers determine their initial offers based on the purity recorded on the item 2.

Calculating Scrap Gold Value

The market value of scrap gold is calculated by referencing the LBMA gold fix, a twice-daily price-setting process that provides a consistent benchmark for the UK industry 3 4. Because this price is usually quoted in US dollars per troy ounce, it must be converted to British pounds and adjusted for grams 6 4. One troy ounce is equivalent to approximately 31.1 grams 6 5.

The formula for determining the theoretical melt value is: weight in grams multiplied by the purity percentage, multiplied by the current price of pure gold per gram 5 1. However, it is important to note that the melt value is a theoretical ceiling. No buyer pays 100% of the spot price because the scrap must be transported, assayed, melted, and refined, all of which incur costs 1 4.

A close-up view of gold jewellery being weighed on a professional digital scale to determine its scrap value.
A close-up view of gold jewellery being weighed on a professional digital scale to determine its scrap value.

Factors Influencing Your Payout

The final amount a seller receives is a result of the dealer's margin, which covers their business expenses and profit 1 4. Specialist gold buyers often pay between 70% and 90% of the melt value, while other high-street outlets or pawn-style shops may offer lower percentages, typically ranging from 35% to 60% of the melt value, due to higher retail overheads and inventory risks 1 2 7.

Non-gold components will also reduce the payout. When a piece is weighed, any non-precious materials such as gemstones, watch movements, springs, or base metal cores must be removed or accounted for 6 2. Sellers should expect a professional buyer to sort items by carat and weigh them separately, rather than placing an entire mixed collection of items on a scale at once 6 2.

Standard Weighing and Verification Practices

Accuracy is vital in the trading process. Reputable buyers use scales that are verified as legal for trade, and the weight should be clearly visible to the customer throughout the assessment 6. If a seller intends to weigh their own items at home, they should be aware that standard kitchen scales often lack the precision required for high-value transactions; a scale with at least 0.01-gram resolution is generally recommended for reliable results 6 2.

During the verification process, buyers may use acid tests or X-ray fluorescence (XRF) machines to confirm the purity of the metal 2. This ensures the item matches the hallmark and prevents errors caused by misidentified or base-metal-filled jewellery. Being aware of these professional standards helps sellers evaluate whether a buyer is conducting a thorough and honest assessment 2.

Consumer Requirements and Regulatory Protections

In the UK, the trade of scrap precious metals is subject to regulatory standards intended to ensure market integrity and prevent criminal activity. Sellers are required to provide valid photographic identification and, in many cases, proof of address when completing a sale 6. These checks are a standard legal obligation for professional metal dealers, not an optional step, and help maintain transparency in the secondary gold market.

To ensure a fair transaction, sellers are encouraged to compare offers from multiple professional buyers. Because margins can vary significantly between different business models, gathering several quotes based on a known weight and purity can provide a clearer picture of the current market conditions for scrap gold 8 9.

Sources

  1. Scrap Gold vs Melt Value: What's the Difference & How Much Will Dealers Pay? (2026): https://londongoldexchange.co.uk/blog/scrap-gold-vs-melt-value-explained
  2. How to Calculate Scrap Gold Value: Step-by-Step Method: https://goldcalculator.co/blog/how-to-calculate-scrap-gold-value/
  3. How Gold Selling Prices Are Calculated in the UK: https://goldbuyercheck.co.uk/how-gold-selling-prices-are-calculated-in-the-uk/
  4. How do gold buyers make money, and how much do they pay? - Milleso: https://milleso.com/articles/how-do-gold-buyers-make-money
  5. Scrap gold price UK: how much is your gold worth per gram? | Gold Arthur: https://goldarthur.co.uk/articles/scrap-gold-price-uk-how-much-is-your-gold-worth/
  6. How Scrap Gold and Silver Are Weighed - The Gold Exchange: https://thegoldexchange.com/how-scrap-gold-is-weighed/
  7. Pawnshops vs Gold Dealers: Which Pays More for Gold?: https://goldbuyercheck.co.uk/selling-gold-to-pawnshops-vs-gold-dealers-which-pays-more/
  8. Gold Buyer Comparison: What Different Buyers Really Pay: https://www.gold-traders.co.uk/blog/gold-buyer-price-comparison/
  9. Where to Sell Gold in the UK (2026) | MetalsAlpha: https://www.metalsalpha.com/guides/where-to-sell-gold-uk


Disclaimer: The information on this site is of a general nature only and is not intended to address the specific circumstances of any particular individual or entity. It is not intended or implied to be a substitute for professional advice.