How much does a 1.00 to 1.49ct G SI1 natural round diamond cost?

As of October 2026, 1.00 to 1.49ct G SI1 natural round diamonds typically cost £1,704 GBP to £4,910 GBP, with a median price of £2,735 GBP. There are currently 3,775 diamonds matching this specification available across retailers.

Where can I find the best price on a G SI1 round diamond?

About 35% of these diamonds are available at multiple retailers, with an average price spread of 52%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct G SI1 Natural Round

Quick answer

As of October 2026, there are 3,775 natural round diamonds with G colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £1,704 GBP to £4,910 GBP, with a median of £2,735 GBP. At least 68 retailers stock this exact specification, and 35% of the stones appear at more than one of them, with an average price spread of 52%. Half of all listings fall between £2,068 GBP and £3,360 GBP per carat. The same specification in lab grown form lists at a median of about £309 GBP per carat. Over the last 30 days the median price moved -0.5% and the number of listings moved +4.4%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, September 2026: natural diamonds at 2,335 USD per carat and lab-grown at 443 USD per carat, a natural to lab ratio of 5.3 to 1. Round natural stones in the index: 2,248 USD per carat, +7.6% month on month. See the full index release

Figures come from current listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: October 2026

Available

3,775

Lowest Price

£752 GBP

Highest Price

£10,051 GBP

Average Price

£3,102 GBP