How the gram price is derived
Although Chinese 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 CNY 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.
Chinese domestic gold trades on the Shanghai Gold Exchange (SGE), which quotes gold in yuan per gram. The SGE benchmark usually tracks the international XAU/USD price converted at the USD/CNY rate, sometimes with a local premium or discount reflecting domestic supply and demand.