How much does a 1.00 to 1.49ct I I1 natural round diamond cost?

As of September 2026, 1.00 to 1.49ct I I1 natural round diamonds typically cost £863 GBP to £2,846 GBP, with a median price of £1,556 GBP. There are currently 1,097 diamonds matching this specification available across retailers.

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

About 54% of these diamonds are available at multiple retailers, with an average price spread of 51%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct I I1 Natural Round

Quick answer

As of September 2026, there are 1,097 natural round diamonds with I colour and I1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £863 GBP to £2,846 GBP, with a median of £1,556 GBP. At least 31 retailers stock this exact specification, and 54% of the stones appear at more than one of them, with an average price spread of 51%. Half of all listings fall between £1,148 GBP and £1,900 GBP per carat. The same specification in lab grown form lists at a median of about £1,461 GBP per carat. Over the last 30 days the median price moved -4.5% and the number of listings moved +8.6%.

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

1,097

Lowest Price

£399 GBP

Highest Price

£7,915 GBP

Average Price

£1,732 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

54.0%

Price Spread

51.2%

30-Day Price Trend

-4.5%

30-Day Supply Change

+8.6%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$1,981/ct

10th Percentile

$1,192

Median

$1,981

90th Percentile

$3,225

Score Distribution

1.1K diamonds scored across 4 quality tiers

Excellent

102 (9.3%)

Very Good

330 (30.1%)

Good

316 (28.8%)

Average

349 (31.8%)

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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