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

As of November 6, 2026, 1.50 to 1.99ct K SI1 lab grown round diamonds typically cost $1,351 AUD to $2,020 AUD, with a median price of $1,618 AUD. There are currently 92 diamonds matching this specification available across retailers.

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

About 58% of these diamonds are available at multiple retailers, with an average price spread of 27%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct K SI1 Lab Grown Round

Quick answer

As of November 6, 2026, there are 92 lab grown round diamonds with K colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $1,351 AUD to $2,020 AUD, with a median of $1,618 AUD. Half of all listings fall between $887 AUD and $1,125 AUD per carat. The same specification in natural form lists at a median of about $3,961 AUD per carat. Over the last 30 days the median price moved -5.5% and the number of listings moved +0.3%.

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

Caratlytics Diamond Price Index, October 2026: natural diamonds at 2,202 USD per carat and lab-grown at 462 USD per carat, a natural to lab ratio of 4.8 to 1. Round lab grown stones in the index: 425 USD per carat, +1.7% month on month. See the full index release

Figures come from current listings across more than 125 retailers. The index is a monthly release.

Last updated: November 6, 2026

Available

Lowest Price

$1,334 AUD

Highest Price

$6,451 AUD

Average Price

$1,689 AUD

Market Intelligence

Cross Retailer %

57.6%

Price Spread

26.8%

30-Day Price Trend

-5.5%

30-Day Supply Change

+0.3%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$623/ct

10th Percentile

$619

Median

$623

90th Percentile

$790

Score Distribution

92 diamonds scored across 3 quality tiers

Excellent

51 (55.4%)

Very Good

37 (40.2%)

Good

4 (4.3%)

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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