How this calculator works
The calculator starts from the live 24K gold price per troy ounce, converted to GBP at the current exchange rate. Your weight is converted to grams (1 troy ounce = 31.1034768 g, 1 tola = 11.6638038 g), and the value is adjusted for purity — the multiplier is simply the karat divided by 24, so 22K/916 gold uses 22 ÷ 24 ≈ 0.9167. The formula: value = grams × pure gram price × purity, plus any premium and minus any discount you enter.
In the UK, everyday jewellery is most commonly 9K (375) or 18K (750) rather than 22K, and every piece above a minimal weight must carry a legal hallmark struck by an assay office such as London or Birmingham. 22K and 24K pieces are mostly limited to bullion-style jewellery and coins.