How much does a 1.00 to 1.49ct E SI1 lab grown radiant diamond cost?

As of October 2026, 1.00 to 1.49ct E SI1 lab grown radiant diamonds typically cost £109 GBP to £584 GBP, with a median price of £348 GBP. There are currently 290 diamonds matching this specification available across retailers.

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

About 36% of these diamonds are available at multiple retailers, with an average price spread of 83%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct E SI1 Lab Grown Radiant

Quick answer

As of October 2026, there are 290 lab grown radiant diamonds with E colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £109 GBP to £584 GBP, with a median of £348 GBP. At least 39 retailers stock this exact specification, and 36% of the stones appear at more than one of them, with an average price spread of 83%. Half of all listings fall between £186 GBP and £459 GBP per carat. The same specification in natural form lists at a median of about £3,050 GBP per carat. Over the last 30 days the median price moved +4.0% and the number of listings moved +30.2%.

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. Radiant lab grown stones in the index: 474 USD per carat, -2.1% 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

290

Lowest Price

£87 GBP

Highest Price

£1,438 GBP

Average Price

£366 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

35.6%

Price Spread

83.2%

30-Day Price Trend

+4.0%

30-Day Supply Change

+30.2%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$437/ct

10th Percentile

$158

Median

$437

90th Percentile

$970

Score Distribution

389 diamonds scored across 4 quality tiers

Excellent

83 (21.3%)

Very Good

63 (16.2%)

Good

172 (44.2%)

Average

71 (18.3%)

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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