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

As of October 2026, 3.00 to 4.99ct I SI1 lab grown oval diamonds typically cost £575 GBP to £28,377 GBP, with a median price of £2,014 GBP. There are currently 5 diamonds matching this specification available across retailers.

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

About 8% of these diamonds are available at multiple retailers, with an average price spread of 86%. A comparison tool like Carat Hunter lets you see all the prices side by side.

3.00 to 4.99ct I SI1 Lab Grown Oval

Quick answer

As of October 2026, there are 5 lab grown oval diamonds with I colour and SI1 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run £575 GBP to £28,377 GBP, with a median of £2,014 GBP. At least 24 retailers stock this exact specification, and 8% of the stones appear at more than one of them, with an average price spread of 86%. Half of all listings fall between £243 GBP and £657 GBP per carat. The same specification in natural form lists at a median of about £10,347 GBP per carat. Over the last 30 days the median price moved +6.2% and the number of listings moved +20.9%.

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. Oval lab grown stones in the index: 453 USD per carat, -7.4% 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

£415 GBP

Highest Price

£46,609 GBP

Average Price

£7,848 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

7.5%

Price Spread

86.4%

30-Day Price Trend

+6.2%

30-Day Supply Change

+20.9%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$641/ct

10th Percentile

$241

Median

$641

90th Percentile

$1,454

Score Distribution

11 diamonds scored across 4 quality tiers

Excellent

1 (9.1%)

Very Good

2 (18.2%)

Good

2 (18.2%)

Average

6 (54.5%)

Find Your Diamond

Search 5 I SI1 oval diamonds and compare prices.

Search Diamonds

Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

I SI2SI2 inclusions are not visible without magnification

Save 39%

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