How much does a 0.20 to 0.49ct I SI1 natural round diamond cost?

As of October 2026, 0.20 to 0.49ct I SI1 natural round diamonds typically cost €229 EUR to €625 EUR, with a median price of €375 EUR. There are currently 7,334 diamonds matching this specification available across retailers.

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

About 31% of these diamonds are available at multiple retailers, with an average price spread of 58%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.20 to 0.49ct I SI1 Natural Round

Quick answer

As of October 2026, there are 7,334 natural round diamonds with I colour and SI1 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run €229 EUR to €625 EUR, with a median of €375 EUR. At least 36 retailers stock this exact specification, and 31% of the stones appear at more than one of them, with an average price spread of 58%. Half of all listings fall between €923 EUR and €1,624 EUR per carat. The same specification in lab grown form lists at a median of about €924 EUR per carat. Over the last 30 days the median price moved -10.9% and the number of listings moved +8.5%.

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 natural stones in the index: 2,248 USD per carat, +7.6% 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

7,334

Lowest Price

€92 EUR

Highest Price

€1,728 EUR

Average Price

€412 EUR

Market Intelligence

Retailers Selling

Cross Retailer %

30.7%

Price Spread

58.5%

30-Day Price Trend

-10.9%

30-Day Supply Change

+8.5%

Volatility (30d)

0.03

Price Range

Price per carat distribution across retailers

$1,335/ct

10th Percentile

$815

Median

$1,335

90th Percentile

$2,525

Score Distribution

12.3K diamonds scored across 4 quality tiers

Excellent

2,872 (23.4%)

Very Good

3,876 (31.5%)

Good

3,128 (25.4%)

Average

2,416 (19.7%)

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Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

J SI1J colour is visually identical to I to the naked eye

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I SI2SI2 inclusions are not visible without magnification

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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