How do you calculate the value of 18-carat gold in CHF?

To determine the value of 18-carat gold in CHF, adjust the spot price of gold to reflect the 75% purity level of 18-carat gold. The spot price, quoted in troy ounces in USD, must be converted into CHF and adjusted for purity. For instance, if the spot price is $1,500 per troy ounce, the value of 18-carat gold would equate to 75% of that price when converted to CHF.