The ideal gold chain size for women can vary depending on personal preference, neck size, and the style of the chain. Generally, a standard length for women's gold chains is between 16 and 20 inches. A 16-inch chain will sit high on the neck, while a 20-inch chain will rest on the collarbone.

Men's gold chains is between 20 and 24 inches. A 20-inch chain will sit at the collarbone, while a 24-inch chain will fall just below it. 

To determine the best length for a gold chain, it's important to consider the neckline of the outfit it will be paired with. A shorter chain is ideal for a high neckline, while a longer chain can complement a lower neckline. Additionally, the thickness and style of the chain can affect its overall length and appearance.

Ultimately, the ideal gold chain size for women is one that is comfortable, complements their personal style, and enhances the overall look of their outfit.