How much does a 5.00ct+ K SI1 natural round diamond cost?

As of November 6, 2026, 5.00ct+ K SI1 natural round diamonds typically cost $65,701 SGD to $179,234 SGD, with a median price of $89,191 SGD. There are currently 187 diamonds matching this specification available across retailers.

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

About 34% of these diamonds are available at multiple retailers, with an average price spread of 35%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ K SI1 Natural Round

Quick answer

As of November 6, 2026, there are 187 natural round diamonds with K colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run $65,701 SGD to $179,234 SGD, with a median of $89,191 SGD. Half of all listings fall between $13,942 SGD and $19,740 SGD per carat. Over the last 30 days the median price moved -1.4% and the number of listings moved +1.3%.

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 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

187

Lowest Price

$40,656 SGD

Highest Price

$440,209 SGD

Average Price

$111,257 SGD

Market Intelligence

Cross Retailer %

34.2%

Price Spread

35.0%

30-Day Price Trend

-1.4%

30-Day Supply Change

+1.3%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$12,978/ct

10th Percentile

$9,708

Median

$12,978

90th Percentile

$19,598

Score Distribution

187 diamonds scored across 4 quality tiers

Excellent

35 (18.7%)

Very Good

42 (22.5%)

Good

43 (23.0%)

Average

67 (35.8%)

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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