What is 18k gold?
Last updated 17 October 2026
18k gold contains 75% gold and 25% other metals by weight, and is also described as 18ct or 750 gold. The remaining metals can produce yellow, white, rose or other colours, so 18k does not describe one shade. Its hardness depends on the alloy and how it is made. The higher gold content is a purity distinction, while suitability for everyday wear depends on the finished design and its care.
| Description | Gold content | What it means |
|---|---|---|
| 9ct or 375 | 37.5% | 9 parts gold in 24; 375 parts in 1,000 |
| 14k, calculated as 14/24 | About 58.3% | The mathematical karat fraction |
| 585, a common 14k standard | 58.5% | 585 parts gold in 1,000 |
| 18k, 18ct or 750 | 75% | 18 parts gold in 24; 750 parts in 1,000 |
Choose the alloy colour separately
Yellow, white and rose 18k gold all share the same gold proportion, but their remaining metals differ. Compare actual samples and finishes, and ask whether a white-gold piece has rhodium plating. Its surface finish can affect both appearance and future care.
Check the design and care together
For a ring, look at the band and setting construction as well as the metal specification. Discuss suitable cleaning and inspection with the jeweller, especially where gemstones or coatings are present. A higher purity does not remove the need to care for the complete piece.
Frequently asked questions
- Is 18k gold worth it?
- It can be worth choosing if you prefer the particular alloy colour and want a higher gold content. Compare finished pieces and current quotes for the same design, stone and size. The 18k mark gives the gold proportion, but does not by itself establish better workmanship or a fixed price premium.
- Does 18k gold scratch easily?
- 18k gold can scratch, but it is not always softer than every 14k or 9ct alloy. Composition and processing affect hardness, and the design and wear affect visible marks. Ask a jeweller whether refinishing is appropriate for the condition of the piece rather than assuming every scratch should be polished out.
- Is 18k gold hypoallergenic?
- The 18k mark does not guarantee that a piece is hypoallergenic. It identifies the gold content while leaving 25% for other metals. If you have a known sensitivity, ask for the full alloy composition and details of any coating or solder instead of choosing by purity alone.
Talk through 18k gold with us
Tell us what you have in mind, even if it is only a budget and a piece of jewellery type, and we will help you weigh up the options. We reply to every enquiry, usually within one business day.
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