How much does a 1.00 to 1.49ct I I1 lab grown round diamond cost?

As of September 2026, 1.00 to 1.49ct I I1 lab grown round diamonds typically cost £469 GBP to £3,277 GBP, with a median price of £1,693 GBP. There are currently 129 diamonds matching this specification available across retailers.

Where can I find the best price on a I I1 round diamond?

About 36% of these diamonds are available at multiple retailers, with an average price spread of 71%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct I I1 Lab Grown Round

Quick answer

As of September 2026, there are 129 lab grown round diamonds with I colour and I1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £469 GBP to £3,277 GBP, with a median of £1,693 GBP. At least 19 retailers stock this exact specification, and 36% of the stones appear at more than one of them, with an average price spread of 71%. Half of all listings fall between £1,104 GBP and £2,147 GBP per carat. The same specification in natural form lists at a median of about £1,649 GBP per carat. Over the last 30 days the median price moved -14.2% and the number of listings moved -50.0%.

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

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Round lab grown stones in the index: 438 USD per carat, -14.1% month on month. See the full index release

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

Last updated: September 2026

Available

129

Lowest Price

£324 GBP

Highest Price

£4,620 GBP

Average Price

£1,853 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

35.9%

Price Spread

70.5%

30-Day Price Trend

-14.2%

30-Day Supply Change

-50.0%

Volatility (30d)

0.03

Price Range

Price per carat distribution across retailers

$1,994/ct

10th Percentile

$921

Median

$1,994

90th Percentile

$3,949

Score Distribution

129 diamonds scored across 3 quality tiers

Very Good

27 (20.9%)

Good

58 (45.0%)

Average

44 (34.1%)

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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