How much does a 1.00 to 1.49ct I SI1 natural round diamond cost?

As of September 2026, 1.00 to 1.49ct I SI1 natural round diamonds typically cost $1,890 USD to $4,825 USD, with a median price of $2,744 USD. There are currently 7,001 diamonds matching this specification available across retailers.

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

Compare prices across retailers on Carat Hunter to see all your options.

1.00 to 1.49ct I SI1 Natural Round

Quick answer

As of September 2026, there are 7,001 natural round diamonds with I color and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run $1,890 USD to $4,825 USD, with a median of $2,744 USD. At least 64 retailers stock this exact specification. Half of all listings fall between $2,387 USD and $3,234 USD per carat. The same specification in lab grown form lists at a median of about $2,111 USD per carat.

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

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Round natural stones in the index: 2,094 USD per carat, -3.8% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

7,001

Lowest Price

$375 USD

Highest Price

$15,697 USD

Average Price

$3,092 USD

Market Intelligence

Retailers Selling

Price Spread

30.4%

Price Range

Price per carat distribution across retailers

$2,783/ct

10th Percentile

$2,041

Median

$2,783

90th Percentile

$3,908

Score Distribution

7.0K diamonds scored across 4 quality tiers

Excellent

1,374 (19.6%)

Very Good

2,189 (31.3%)

Good

2,105 (30.1%)

Average

1,333 (19.0%)

Find Your Diamond

Search 7,001 I SI1 round diamonds and compare prices.

Search Diamonds

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

Save 24%

I SI2SI2 inclusions are not visible without magnification

Save 17%

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