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

As of September 2026, 1.00 to 1.49ct I SI1 lab grown round diamonds typically cost $669 USD to $2,618 USD, with a median price of $1,375 USD. There are currently 732 diamonds matching this specification available across retailers.

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

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1.00 to 1.49ct I SI1 Lab Grown Round

Quick answer

As of September 2026, there are 732 lab grown round diamonds with I color and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run $669 USD to $2,618 USD, with a median of $1,375 USD. At least 28 retailers stock this exact specification. Half of all listings fall between $1,411 USD and $4,547 USD per carat. The same specification in natural form lists at a median of about $3,086 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 lab grown stones in the index: 438 USD per carat, -14.1% 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

732

Lowest Price

$138 USD

Highest Price

$11,026 USD

Average Price

$1,675 USD

Market Intelligence

Retailers Selling

Price Spread

91.5%

Price Range

Price per carat distribution across retailers

$3,427/ct

10th Percentile

$1,268

Median

$3,427

90th Percentile

$5,323

Score Distribution

732 diamonds scored across 4 quality tiers

Excellent

138 (18.9%)

Very Good

478 (65.3%)

Good

53 (7.2%)

Average

63 (8.6%)

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

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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