How much does a 1.50 to 1.99ct I SI1 lab grown round diamond cost?

As of October 2026, 1.50 to 1.99ct I SI1 lab grown round diamonds typically cost $1,462 SGD to $4,246 SGD, with a median price of $1,833 SGD. There are currently 439 diamonds matching this specification available across retailers.

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

About 43% of these diamonds are available at multiple retailers, with an average price spread of 91%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct I SI1 Lab Grown Round

Quick answer

As of October 2026, there are 439 lab grown round diamonds with I colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $1,462 SGD to $4,246 SGD, with a median of $1,833 SGD. At least 35 retailers stock this exact specification, and 43% of the stones appear at more than one of them, with an average price spread of 91%. Half of all listings fall between $1,162 SGD and $2,387 SGD per carat. The same specification in natural form lists at a median of about $6,016 SGD per carat. Over the last 30 days the median price moved -8.1% and the number of listings moved +9.7%.

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

439

Lowest Price

$244 SGD

Highest Price

$7,654 SGD

Average Price

$2,571 SGD

Market Intelligence

Retailers Selling

Cross Retailer %

43.0%

Price Spread

90.7%

30-Day Price Trend

-8.1%

30-Day Supply Change

+9.7%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$1,053/ct

10th Percentile

$462

Median

$1,053

90th Percentile

$1,978

Score Distribution

830 diamonds scored across 4 quality tiers

Excellent

394 (47.5%)

Very Good

52 (6.3%)

Good

71 (8.6%)

Average

313 (37.7%)

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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