How much does a 4 carat lab-grown diamond cost?

As of September 2026, a 4 carat lab-grown emerald cut diamond typically sells for $3,230–$4,930, with a fair market price of $4,150. Based on 31 live listings, updated 2026-09-07. Source: The Diamond Price (thediamondprice.com).

How are these prices calculated?

Every figure on this page is computed from live retailer listings, not a fixed price list or a manual estimate. Prices are grouped into matched quality bands (same shape, carat, color and clarity range) rather than blended across the whole market, so the number describes a comparable stone. A band needs at least 20 current listings before we publish a figure for it - below that we show nothing rather than a number we cannot stand behind. Full methodology: thediamondprice.com/research/methodology/

Is an emerald cut diamond cheaper than a round?

In the listings we track, round is consistently the most expensive shape at equivalent carat and quality - rounds waste more rough stone in cutting and carry the most demand. An emerald cut typically lists below round, but the size of the gap varies by carat and by quality band, so the per-carat table on this page is the reliable comparison rather than a single headline percentage.

Why do two diamonds of the same carat differ so much in price?

Carat sets the starting point, but cut, color, clarity, fluorescence and certification move the final price substantially. Cut quality has the largest visible effect: a well-cut stone returns more light and looks brighter than a larger, poorly-cut one. Two stones listed at the same carat weight can differ by several thousand dollars once those factors are accounted for.

How often are these prices updated?

Listings refresh continuously from live retailer feeds, and the banded figures on this page are recalculated from a daily market snapshot, so the prices shown reflect the current market rather than a periodic manual update.

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4 Carat Lab-Grown Emerald Diamond Prices

Fair Market Price:

$4,150

View All Diamonds →

Best Deal:

-11% $2,880

See Best Deal →

Current Market Range:

$3,230 – $4,930

Browse This Range →

Today's Recommendation

Excellent time to buy

Moderate confidence · Based on 31 diamonds

We don't have enough price history for this exact combination yet, so this reflects today's live listings only: 28.0% currently qualify as strong deals.

Why?

✓ 28.0% of listings checked qualify as strong deals

4 Carat Emerald Price History

Price index for lab-grown emerald diamonds moved −33.3% since we began tracking.

1 month +1.2%

16 months −33.3%

Jun 2025 230 days measured of 458 · E–F colour, VVS1–VVS2 clarity Sep 2026

The Diamond Price Index tracks the median asking price of every comparable lab-grown emerald diamond listed each day, indexed to 100 at the start. It shows how the market has moved; for what a stone costs today, see the fair market price above.

Best 4 carat emerald deals right now

Best deal

4.06 ct · H · VS1

$2,880

▼ 31% under fair price

4.03 ct · G · SI1

$3,230

Based on 500,000+ diamonds tracked in real time · How we compute fair prices

Emerald engagement rings

Market Analysis What this means for you

Supply is thin for this spec right now.
31 comparable diamonds analyzed — buyers have limited negotiating power.
Best listing today is 11% below what comparable diamonds start at.
You shouldn’t pay more than $3,297 for this spec.

Price distribution 31 listings

3 diamonds
$2,880–$3,071 5 diamonds
$3,071–$3,262 1 diamond
$3,262–$3,453 4 diamonds
$3,453–$3,644 0 diamonds
$3,644–$3,835 0 diamonds
$3,835–$4,025 5 diamonds
$4,025–$4,216 3 diamonds
$4,216–$4,407 0 diamonds
$4,407–$4,598 1 diamond
$4,598–$4,789 8 diamonds
$4,789–$4,980 1 above
over $4,980

Fair market
$4,150 Best deal
$2,880

Best $2,880 Fair $4,150

Fair market price: $4,150
Typical market range: $3,230 – $4,930
Best deal today: $2,880 11% below

Emerald by carat market range

4 Carat Diamond Prices Table

Below are the current 4 carat lab-grown diamond prices for the most popular diamond shapes. Each price is the median of the diamonds listed right now at this size and quality band. Click a shape for detail.

Shape	Typical price range	vs Round	Live stones
4ct Marquise View details →	$5,060 – $6,050	▼ 13% less than round	33
4ct Heart View details →	$5,200 – $6,200	▼ 7% less than round	45
4ct Princess View details →	$5,330 – $6,170	▼ 4% less than round	111
4ct Emerald View details →	$5,030 – $6,620	▼ 3% less than round	39
4ct Cushion View details →	$5,970 – $7,020	▼ 2% less than round	23
4ct Oval View details →	$5,290 – $6,120	▼ 1% less than round	137
4ct Radiant View details →	$5,170 – $6,970	Same	52
4ct Round View details →	$5,680 – $6,160	Reference	163
4ct Pear View details →	$5,160 – $6,210	▲ 1% more than round	56

Each figure is the median asking price of that shape’s live listings — not a like-for-like comparison between shapes. Cut grade is the biggest single driver of a diamond’s price, and our retailers don’t publish it, so we won’t tell you one shape is cheaper than another when we can’t hold cut constant.

Compare another shape at 4 ct

Frequently Asked Questions

The price of a 4 carat emerald diamond varies significantly based on the 4Cs (cut, color, clarity, and carat). On average, you can expect to pay anywhere from $2,000 to $25,000+ depending on quality. Use our price index above to see current market prices.

4 carat is a popular choice for engagement rings, offering excellent visibility and presence on the finger. It strikes a balance between size and value, making it one of the most sought-after carat weights.

Diamond prices fluctuate based on market supply and demand, currency exchange rates, mining output, and consumer trends. Seasonal factors like engagement season can also affect prices. Tracking historical prices helps you identify the best time to buy.

Both natural and lab-grown diamonds are genuine diamonds with identical physical properties. Lab-grown diamonds typically cost 40-60% less than natural diamonds of equivalent quality. Your choice depends on personal preference, budget, and values.

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4 Carat Lab-Grown Emerald Diamond Prices

4 Carat Emerald Price History

Best 4 carat emerald deals right now

Emerald engagement rings

4 Carat Diamond Prices Table

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Why Track Emerald Diamond Prices?

What Affects 4 Carat Diamond Prices?

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