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

As of October 2026, 1.00 to 1.49ct H SI1 natural round diamonds typically cost £1,629 GBP to £4,492 GBP, with a median price of £2,557 GBP. There are currently 4,046 diamonds matching this specification available across retailers.

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

About 37% of these diamonds are available at multiple retailers, with an average price spread of 46%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct H SI1 Natural Round

Quick answer

As of October 2026, there are 4,046 natural round diamonds with H colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £1,629 GBP to £4,492 GBP, with a median of £2,557 GBP. At least 72 retailers stock this exact specification, and 37% of the stones appear at more than one of them, with an average price spread of 46%. Half of all listings fall between £1,787 GBP and £2,767 GBP per carat. The same specification in lab grown form lists at a median of about £771 GBP per carat. Over the last 30 days the median price moved -0.7% and the number of listings moved +7.4%.

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

4,046

Lowest Price

£858 GBP

Highest Price

£8,995 GBP

Average Price

£2,867 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

37.0%

Price Spread

46.1%

30-Day Price Trend

-0.7%

30-Day Supply Change

+7.4%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$2,833/ct

10th Percentile

$2,039

Median

$2,833

90th Percentile

$4,964

Score Distribution

8.2K diamonds scored across 4 quality tiers

Excellent

1,114 (13.6%)

Very Good

1,953 (23.9%)

Good

1,670 (20.4%)

Average

3,436 (42.0%)

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Consider Instead

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

H SI2SI2 inclusions are not visible without magnification

Save 16%

Lab-Grown H SI1Same specifications, lab-grown origin

Save 54%

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