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

As of November 2026, 1.00 to 1.49ct I SI1 natural round diamonds typically cost €1,724 EUR to €4,917 EUR, with a median price of €2,667 EUR. There are currently 2,854 diamonds matching this specification available across retailers.

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

About 37% of these diamonds are available at multiple retailers, with an average price spread of 46%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct I SI1 Natural Round

Quick answer

As of November 2026, there are 2,854 natural round diamonds with I colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run €1,724 EUR to €4,917 EUR, with a median of €2,667 EUR. At least 71 retailers stock this exact specification, and 37% of the stones appear at more than one of them, with an average price spread of 46%. Half of all listings fall between €2,128 EUR and €3,290 EUR per carat. The same specification in lab grown form lists at a median of about €919 EUR per carat. Over the last 30 days the median price moved +0.3% and the number of listings moved +7.9%.

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: November 2026

Available

2,854

Lowest Price

€843 EUR

Highest Price

€10,189 EUR

Average Price

€3,052 EUR