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 $1,138 SGD to $9,825 SGD, with a median price of $3,288 SGD. 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 18% of these diamonds are available at multiple retailers, with an average price spread of 267%. 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 $1,138 SGD to $9,825 SGD, with a median of $3,288 SGD. At least 29 retailers stock this exact specification, and 18% of the stones appear at more than one of them, with an average price spread of 267%. Half of all listings fall between $445 SGD and $2,628 SGD per carat. The same specification in natural form lists at a median of about $17,319 SGD per carat. Over the last 30 days the median price moved -33.4% and the number of listings moved -16.8%.

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

$474 SGD

Highest Price

$38,208 SGD

Average Price

$6,241 SGD

Market Intelligence

Retailers Selling

Cross Retailer %

17.8%

Price Spread

267.2%

30-Day Price Trend

-33.4%

30-Day Supply Change

-16.8%

Volatility (30d)

0.05

Price Range

Price per carat distribution across retailers

$639/ct

10th Percentile

$153

Median

$639

90th Percentile

$2,696

Score Distribution

21 diamonds scored across 4 quality tiers

Excellent

5 (23.8%)

Very Good

4 (19.0%)

Good

4 (19.0%)

Average

8 (38.1%)

Find Your Diamond

Search 9 I SI1 round 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 19%

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