How much does a 1.50 to 1.99ct K I1 natural round diamond cost?

As of November 6, 2026, 1.50 to 1.99ct K I1 natural round diamonds typically cost $2,705 AUD to $8,407 AUD, with a median price of $4,667 AUD. There are currently 305 diamonds matching this specification available across retailers.

Where can I find the best price on a K I1 round diamond?

About 35% of these diamonds are available at multiple retailers, with an average price spread of 65%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct K I1 Natural Round

Quick answer

As of November 6, 2026, there are 305 natural round diamonds with K colour and I1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $2,705 AUD to $8,407 AUD, with a median of $4,667 AUD. Half of all listings fall between $2,268 AUD and $4,270 AUD per carat. The same specification in lab grown form lists at a median of about $1,122 AUD per carat. Over the last 30 days the median price moved -2.5% and the number of listings moved +4.1%.

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 natural stones in the index: 2,124 USD per carat, -6.9% 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

305

Lowest Price

$1,374 AUD

Highest Price

$17,562 AUD

Average Price

$5,271 AUD

Market Intelligence

Cross Retailer %

35.4%

Price Spread

65.3%

30-Day Price Trend

-2.5%

30-Day Supply Change

+4.1%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$2,146/ct

10th Percentile

$1,183

Median

$2,146

90th Percentile

$3,764

Score Distribution

305 diamonds scored across 4 quality tiers

Excellent

34 (11.1%)

Very Good

85 (27.9%)

Good

46 (15.1%)

Average

140 (45.9%)

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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