How Much is a 1 Carat Diamond?
Updated for 2025. Analysis of current market prices for Natural vs Lab Grown diamonds at the 1ct weight class.
The Short Answer
Natural Market: Expect to pay between $3,500 and $8,000 for a good quality 1 carat natural diamond.
Lab Grown Market: Expect to pay between $500 and $1,000 for a similar quality lab-grown stone.
*Prices are based on GIA/IGI certified stones with G-H Color and VS Clarity. ideal Cut.
Detailed Price Breakdown
When shopping for a 1 carat diamond, the price is heavily influenced by the "4Cs": Cut, Color, Clarity, and Carat. However, the origin (Natural vs. Lab) is the biggest price multiplier.
The 1 carat diamond is the benchmark for engagement rings. It is the most popular weight, meaning demand keeps prices firm, but it holds its value well.
Natural vs Lab Grown: The Price Visualized
Natural 1ct
Lab Grown 1ct
How Big is a 1 Carat Diamond?
Carat is a measure of weight, not visual size. However, for a standard round brilliant cut diamond, we can estimate the diameter.
A 1 carat diamond is approximately 6.5 millimeters across. This provides excellent finger coverage.
Where to Buy a 1 Carat Diamond
We recommend buying online to save 30-40% compared to traditional brick-and-mortar stores. Here are our top rated retailers for 1ct stones.
Buying a 1 Carat Diamond Internationally
All prices on this page are quoted in USD from the major US online retailers, which ship diamond jewellery worldwide. If you are buying from the UK, Canada, Australia, Ireland or the EU, the 1ct grading scale is identical — GIA, IGI and HRD all use the same D–Z colour and FL–I3 clarity grades — so a G/VS2 stone in London or Sydney is exactly the same as one in New York.
- UK buyers: Convert USD to GBP at the live rate, then add 20% VAT on imports over £135. A US$5,500 natural 1ct stone typically lands at roughly the same figure in GBP once duty is paid.
- Australian buyers: Add 10% GST on orders over A$1,000 plus a customs entry fee. Most US retailers (James Allen, Blue Nile) ship insured express to AU in 3–5 business days.
- Canadian buyers: GST/HST applies on import (5–15% by province). Diamond purchases over CA$20 are taxable; the certificate and appraisal travel with the stone.
- EU & Irish buyers: VAT ranges from 19–25% depending on the country of import. EU consumer law gives you 14 days to return for a full refund regardless of where the retailer is based.
The same favouritism for colour, clarity and cut applies in every market — there is no separate “UK grade” or “Australian grade” for diamonds. Always insist on a current GIA or IGI report before purchase, especially at 1 carats where small grade differences mean thousands of dollars (or pounds, or Australian dollars).
Compare Other Diamond Sizes
Looking for a different size? Check out our other accurate market pricing guides to find the perfect diamond for your budget.