How the 150 grams of 18k gold price in AUD is calculated
Every figure on this page starts from the global gold spot price, which is quoted in US dollars per troy ounce. Right now that is $4,140 per ounce. A troy ounce weighs 31.1035 grams, so one gram of pure gold costs $133.12. We convert that to Australian Dollar at the live rate of 1 USD = 1.4439 AUD, giving A$192.21 per gram of pure metal.
Because 18K gold is 75.0% pure, we multiply by 0.75, which gives A$144.16 per gram and A$4,484 per troy ounce. Multiplying by the weight of 150 grams gives the headline value of A$21,624. Compared with yesterday's reference price, the value is up 1.89% in AUD terms.
The formula
Value = spot price per ounce ÷ 31.1035 × grams × purity × USD/AUD rate. Our calculator above applies this formula instantly to any weight and purity.
Worked examples with today's numbers
- 10 grams of 24K (999) gold: 10 × A$192.21 × 0.999 = A$1,920
- 10 grams of 23K (958) gold: 10 × A$192.21 × 0.958 = A$1,841
- 10 grams of 22K (916) gold: 10 × A$192.21 × 0.916 = A$1,761
- 10 grams of 21K (875) gold: 10 × A$192.21 × 0.875 = A$1,682
- One kilogram bar of pure gold: A$192,210
What moves the gold price
Gold reacts most to real interest rates, the strength of the US dollar, central-bank buying and demand for safe-haven assets during geopolitical stress. Jewelry demand from India and China adds seasonal swings around Diwali, Akshaya Tritiya and the Lunar New Year.
Roughly half of annual gold demand is jewelry, about a quarter is bars and coins for investment, and the remainder is split between central banks and technology such as electronics and dentistry. In Australian Dollar terms, the exchange rate matters as much as the metal itself: if the AUD weakens against the US dollar, the local price rises even when the dollar price is flat.
Tips before you buy or sell
- Compare dealer quotes with the melt value shown here. A fair buy-back offer for bullion is usually within 2–5% of spot; for jewelry and scrap expect 70–95%.
- Bullion bars and coins carry the smallest premium over spot, while jewelry includes making charges that are rarely recovered when you sell. Always ask for the weight in grams and the karat stamp before comparing offers.
- Weigh items on a calibrated scale in grams. Kitchen scales are often off by more than 1 gram, which can change the value of 150 grams of 18k gold materially.
- Check prices at different times of the day. The market trades almost 24 hours on weekdays and the most liquid period is the London and New York overlap.
- Remember that VAT, import duty and making charges are not included in spot prices. See our methodology for details.
Spot price vs. retail price
The spot price is the wholesale price for large, good-delivery bars traded between banks and refiners. Retail products cost more because of minting, assaying, insurance, shipping and dealer margin. Small coins and bars can carry premiums of 3–10% for gold and 10–30% for silver, while jewelry adds design and labor costs. When you sell, you receive a price based on spot minus the buyer's spread, so the figures on this page are the best neutral reference for negotiating.
Price data is provided by MetalflowAPI and refreshed about every minute. Values are indicative and not an offer to buy or sell.