How the gram price is derived
Although Saudi shops quote per gram, the global market quotes gold in US dollars per troy ounce. One troy ounce equals exactly 31.1034768 grams, so the pure gold (24K) gram price is the ounce price divided by 31.1034768, converted to SAR at the live exchange rate. Lower purities are then a simple multiplication: 22K/916 is the 24K gram price × 0.9167, and 18K is × 0.75.
Saudi gold prices are quoted in riyals per gram for 24K, 22K, 21K and 18K. Because the riyal is pegged to the US dollar, the local price mirrors the international USD spot price almost one-for-one, with VAT applying to jewellery purchases.