2 Carat and 3 Carat Lab-Grown Diamond Price: What You Pay and What You Get

A 2 carat round lab-grown diamond measures about 8.1 mm across. A natural stone of the same size and grades costs many times more. That gap is why so many buyers who planned on 1 carat end up looking at 2 or 3. At these sizes, though, cut and measurements matter even more than at 1 carat, because every flaw in proportion shows across a bigger table.

In October 2026 the average online asking price for a loose 2 carat lab-grown diamond (D–K, FL–SI2) was about $1,000, and for a 3 carat about $1,550. Natural 2 carat stones averaged over $17,000. The range inside lab-grown is wide: a 2 carat runs from about $500 to $2,600 and a 3 carat from about $720 to $4,000. Cut, color, clarity, shape, the report and as-grown status explain the spread. Buy on measurements and cut first, then color and clarity.

2 and 3 carat prices at a glance

StoneAlgo index of online asking prices for loose lab-grown stones, colors D–K, clarity FL–SI2, read on 4 November 2026:

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A 2 carat lab-grown round costs roughly a twentieth of a natural one at the same index. Lab-grown prices have kept falling, so a quote is only good for the day it is given. Wholesale prices are lower again. JCK reported that lab-grown wholesale prices fell 26% across 2025.

2 carat lab-grown diamond price by shape

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Elongated shapes such as oval, pear and marquise look larger face-up for the same weight. Measurements are typical for well-cut stones; deep stones face up smaller.

3 carat lab-grown diamond price by shape

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What moves the price at 2 and 3 carats

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Cut and measurements come first

At 2 carats and up, a poorly proportioned stone shows it: a deep round can measure 7.8 mm and look like a 1.80 ct, while a shallow one leaks light and looks glassy in the center. For rounds, ask for Excellent cut and the diameter. For fancy shapes, ask for the length, width and length-to-width ratio, and look at a video for the bow-tie in ovals, pears and marquise.

Color and clarity at larger sizes

A larger table shows more of the stone, so color and inclusions are easier to see than at 1 carat.

• Color: G–H still looks white in most settings. In a 3 carat emerald or Asscher cut, the open step facets show body color more, so F–G is safer.
• Clarity: VS1–VS2 is usually eye-clean in brilliant cuts. In emerald and Asscher cuts, VS1 or better is the safer choice, because the long step facets work like windows.

Just under the magic sizes

GIA notes that prices step up at “magic sizes” such as 2.00 ct and 3.00 ct. A 1.90 ct or a 2.90 ct stone with an excellent cut is only a fraction of a millimeter smaller, and the price difference can pay for a better color, a better clarity or the setting. If the round number does not matter to you, this is the easiest saving at these sizes.

The report and treatment

At 2 and 3 carats, get a report and check it online. IGI gives full color and clarity grades and states the growth method and treatment findings. GIA’s lab-grown assessment, since October 2025, puts stones into Premium or Standard, which makes it harder to compare two stones directly. GIA has reported that about 80% of the CVD stones it received since 2020 had been treated after growth, mostly to improve color. If you want as-grown, look for the as-grown statement in the report comments.

2 or 3 carat: which size suits what

• Engagement ring solitaire: 2 ct is the common step up from 1 ct. 3 ct reads as a statement stone on most hands; check that the setting and prongs suit the weight.
• Studs: 2.00 ct TCW is two stones of about 1.00 ct each, about 6.4 mm across. A 4.00 ct TCW pair is two 2 ct stones, about 8.1 mm each.
• Pendant: a 2 carat round or oval is visible from across a room. Eye-clean is enough.

2 and 3 carat checklist

2 and 3 carat questions

Written byKai Chen

Sales & Technical Director, NUVU

11+ years supporting global clients with lab-grown diamond product consultation and market analysis.

Credentials: GIA Graduate Diamonds (GD)

About NUVU. NUVU is the international brand of New Perspective Superhard Materials Co., Ltd. in Zhecheng, Henan, China. We grow HPHT lab-grown diamonds in-house and cut, polish and match stones in our own workshop.