What does the world gold price in USD per ounce mean?
XAU is a commonly used code for gold and USD is the US dollar. XAU/USD or USD per ounce states how many US dollars correspond to one troy ounce of gold. It does not use the ordinary avoirdupois ounce.
How do a troy ounce and a Vietnamese lượng differ?
LBMA defines one troy ounce as exactly 31.1034768 grams. Under Appendix IV of Vietnam’s Decree 86/2012/ND-CP, one lượng for gold and silver is 37.5 grams. One lượng is therefore approximately 1.205653 troy ounces.
- 1 troy ounce = 31.1034768 grams
- 1 lượng = 37.5 grams = 10 chỉ
- 1 lượng ≈ 1.205653 troy ounces
Formulas for VND per gram and VND per lượng
Let P be the world gold price in USD per troy ounce and R the selected USD/VND exchange rate:
VND/gram = P × R ÷ 31.1034768VND/lượng = P × R × (37.5 ÷ 31.1034768)VND/lượng ≈ P × R × 1.205653The website uses Vietcombank’s USD transfer-buying rate for its displayed conversion. A different exchange-rate basis produces a different result.
Worked example with illustrative numbers
Assume gold is 2,500 USD per troy ounce and the exchange rate is 25,000 VND per USD:
2,500 × 25,000 ÷ 31.1034768≈ 2,009,422 VND/gram2,500 × 25,000 × 1.205653≈ 75,353,312 VND/lượngThe figures are rounded illustrations of the method and are not current market prices.
Why is the conversion different from a shop’s selling price?
The calculation only converts an international gold quote and a foreign-exchange rate by mass. Vietnamese retail prices can also reflect local supply and demand, brand, product, fineness, fabrication, distribution costs, taxes and the dealer’s buy–sell spread. It is not a transaction quote.
Use the live conversion tool on giavangbac.app
The world-prices page reads XAU/USD, applies Vietcombank’s USD transfer-buying rate and displays an estimated VND per lượng value. You can then compare it with Vietnamese retail quotes.