How much does a 3.00 to 4.99ct I SI1 lab grown round diamond cost?

As of October 2026, 3.00 to 4.99ct I SI1 lab grown round diamonds typically cost €800 EUR to €6,924 EUR, with a median price of €2,794 EUR. There are currently 9 diamonds matching this specification available across retailers.

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

About 19% of these diamonds are available at multiple retailers, with an average price spread of 249%. A comparison tool like Carat Hunter lets you see all the prices side by side.

3.00 to 4.99ct I SI1 Lab Grown Round

Quick answer

As of October 2026, there are 9 lab grown round diamonds with I colour and SI1 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run €800 EUR to €6,924 EUR, with a median of €2,794 EUR. At least 28 retailers stock this exact specification, and 19% of the stones appear at more than one of them, with an average price spread of 249%. Half of all listings fall between €314 EUR and €1,846 EUR per carat. The same specification in natural form lists at a median of about €12,153 EUR per carat. Over the last 30 days the median price moved -38.2% and the number of listings moved -22.5%.

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 lab grown stones in the index: 414 USD per carat, -5.0% 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

Lowest Price

€333 EUR

Highest Price

€26,853 EUR

Average Price

€4,636 EUR

Market Intelligence

Retailers Selling

Cross Retailer %

18.7%

Price Spread

249.1%

30-Day Price Trend

-38.2%

30-Day Supply Change

-22.5%

Volatility (30d)

0.16

Price Range

Price per carat distribution across retailers

$684/ct

10th Percentile

$153

Median

$684

90th Percentile

$2,668

Score Distribution

21 diamonds scored across 4 quality tiers

Excellent

1 (4.8%)

Very Good

7 (33.3%)

Good

5 (23.8%)

Average

8 (38.1%)

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Related Specifications

D IF D VVS1 D VVS2 D VS1 D VS2 D SI1 E IF E VVS1 E VVS2 E VS1 E VS2 E SI1 F IF F VVS1 F VVS2 F VS1 F VS2 F SI1 G IF G VVS1 G VVS2 G VS1 G VS2 G SI1 H IF H VVS1 H VVS2 H VS1 H VS2 H SI1 I IF I VVS1 I VVS2 I VS1 I VS2 I SI1