How much does a 1.50 to 1.99ct K SI2 lab grown round diamond cost?

As of November 6, 2026, 1.50 to 1.99ct K SI2 lab grown round diamonds typically cost £1,360 GBP to £2,035 GBP, with a median price of £1,631 GBP. There are currently 57 diamonds matching this specification available across retailers.

Where can I find the best price on a K SI2 round diamond?

About 51% of these diamonds are available at multiple retailers, with an average price spread of 27%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct K SI2 Lab Grown Round

Quick answer

As of November 6, 2026, there are 57 lab grown round diamonds with K colour and SI2 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run £1,360 GBP to £2,035 GBP, with a median of £1,631 GBP. Half of all listings fall between £887 GBP and £1,126 GBP per carat. The same specification in natural form lists at a median of about £1,800 GBP per carat. Over the last 30 days the median price moved -5.5% and the number of listings moved +0.3%.

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

Caratlytics Diamond Price Index, October 2026: natural diamonds at 2,202 USD per carat and lab-grown at 462 USD per carat, a natural to lab ratio of 4.8 to 1. Round lab grown stones in the index: 425 USD per carat, +1.7% month on month. See the full index release

Figures come from current listings across more than 125 retailers. The index is a monthly release.

Last updated: November 6, 2026

Available

Lowest Price

£648 GBP

Highest Price

£5,282 GBP

Average Price

£1,683 GBP

Market Intelligence

Cross Retailer %

50.9%

Price Spread

26.9%

30-Day Price Trend

-5.5%

30-Day Supply Change

+0.3%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$1,196/ct

10th Percentile

$1,193

Median

$1,196

90th Percentile

$1,518

Score Distribution

57 diamonds scored across 4 quality tiers

Excellent

1 (1.8%)

Very Good

23 (40.4%)

Good

6 (10.5%)

Average

27 (47.4%)

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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