How Much Does a Half Carat Diamond Cost

The median natural half carat diamond costs $995. Lab-grown costs $259. Both figures are from current listings across our index, October 2026, and the spread between them defines every buying decision at this size.

If you need the bigger picture on how carat weight drives price across all sizes, our 1 carat diamond price guide covers the full spectrum with the same methodology. This post is narrower: the half carat, where the data is dense, the market is liquid, and the value case is genuinely strong.

What the full range looks like

We're tracking 1,302,582 natural stones and 302,977 lab-grown stones in the 0.5 to 0.75ct range. That pool is large enough that the medians are stable. No thin-market effects distorting the numbers.

Origin	P10	Median	P90	Median per carat	At 2+ retailers	Certified
Natural	$558	$995	$1,971	$1,709	40%	58%
Lab-grown	$127	$259	$500	$438	50%	64%

Prices from current listings, October 2026.

The lab-grown median is 74% below natural at this specification, a ratio of 3.8 to 1. That ratio is consistent with what we see at other sizes, but the absolute dollar difference here is lower than at 1ct, which matters to buyers who want natural but have a firm budget ceiling.

Two figures in that table deserve attention. Lab-grown stones at this size are more likely to appear at multiple retailers (50% versus 40% for natural) and more likely to be certified (64% versus 58%). More cross-retailer supply means more price competition. More certification means more comparability between stones. Both effects push lab-grown prices down and keep them there.

The colour and clarity cells worth buying

Natural half carats concentrate in D through G colour and VVS1 through VS2 clarity. Those are the most stocked cells because they serve engagement ring buyers. But the premiums between cells are not all justified.

Origin	Colour	Clarity	Stones	Median
Natural	D	VVS1	47,086	$1,404
Natural	D	VVS2	37,805	$1,241
Natural	D	VS1	41,907	$1,210
Natural	D	VS2	35,744	$1,142
Natural	G	VS1	39,816	$1,077
Natural	G	VS2	40,559	$1,020
Natural	F	SI1	35,795	$881
Lab-grown	D	VVS2	82,588	$258
Lab-grown	D	VS1	48,176	$253
Lab-grown	D	VVS1	45,401	$235

The gap between G VS2 ($1,020) and D VVS1 ($1,404) is $384. That's a 37% premium for grades that are genuinely invisible to the naked eye at half a carat. A well-cut G VS2 round faces up white in almost any setting. VS2 clarity at this size is eye-clean universally. The $384 buys you a better certificate, not a visible difference in the stone.

For lab-grown, the spread is almost irrelevant: D VVS2 at $258, D VS1 at $253, D VVS1 at $235. Those differences are noise. Buy a well-cut stone and stop there.

Shape premiums that run in opposite directions

The shape story at this size flips between natural and lab-grown in a useful way.

For natural stones, round brilliant sits highest at $1,087. Every fancy shape comes in below it. Emerald at $819 is the most notable: 25% under round for a shape that looks architecturally distinct and suits angular modern settings. A natural emerald cut at $819 versus a round at $1,087 is $268 saved for a stone with more geometry and less convention. At 0.5ct, a VS2 eye-clean emerald is a straightforward choice. Pear at $909, heart at $881, princess at $875. Oval at $957 comes in below round despite carrying a premium at the 1ct size. Worth noting for buyers who plan to move up in size later.

Lab-grown inverts this entirely. Round is the cheapest shape at $235. Oval ($279), pear ($283), radiant ($284), emerald ($294), marquise ($302), cushion ($361) all sit above it. Cushion commands a 54% premium over round. The explanation is supply: lab-grown round production runs at enormous scale. Fancy shapes haven't caught up yet, so they carry a premium unrelated to quality.

If you want lab-grown and prefer a fancy shape, you'll pay more. If you want natural and prefer a fancy shape, you'll pay less. Consistent pattern, opposite direction.

Why the same stone costs different amounts at different stores

Forty percent of natural half carats in our index appear at more than one retailer. For lab-grown, it's 50%.

That means a substantial share of stones are identically specified, certified, and sitting in multiple stores at different prices. The price variation on a single stone across retailers can be $200 to $400 for naturals at this size. On a $995 median purchase, that's a 20 to 40% gap. There's no quality difference. No service difference. Just different margin structures and inventory pricing assumptions.

Our where-to-buy tool for natural 0.5ct rounds lets you see how prices compare across retailers for the same specification. Use it before committing to any seller. At this size and price point, overpaying by several hundred dollars is genuinely avoidable.

Half carats and the 1 carat jump

Per carat pricing is where the half carat tells its most interesting story. Natural half carats sit at $1,709 per carat in our index. As documented in our diamond price by carat analysis, per carat rates for natural rounds accelerate as you approach the 1ct threshold. The 1ct mark carries a size premium on top of raw weight cost.

A 0.5ct stone at $995 is not simply half the price of a 1ct stone. It's typically well below half, because the 1ct stone carries a premium for crossing a round number that buyers perceive as meaningful. Buyers who genuinely don't need a full carat get real value at this size, and the visual difference between a well-cut 0.5ct and a 0.65ct is marginal to most eyes.

Lab-grown at $259 median for a half carat makes the philosophical dimension of this choice clearer than at any other size. You are not choosing between affordable and expensive. You are choosing between a stone with some connection to supply constraints ($995 median, natural) and one without ($259 median, lab-grown). Both are real diamonds. One costs 3.8 times as much.

The buying rule

For natural: G to H colour, VS2 to SI1 clarity, with an eye-clean check on any SI1. That is the value cell. D and E colour at VVS clarity carry $200 to $400 premiums over G VS2 with no visible payoff at half a carat. If the setting is white gold or platinum, G faces plenty white. If the setting is yellow or rose gold, H or even I faces just as well.

For lab-grown: the grade matters almost nothing at this size in dollar terms. F to H in VS1 to VS2 gets you a well-cut stone for roughly $250 to $290. Chasing D VVS2 over D VS1 saves you $5. Spend that on the setting, or on a better cut report.

On shape for natural: emerald at $819 median is the biggest discount to round at $1,087. Oval ($957) and pear ($909) face up slightly larger than a round of equivalent carat weight and both come in below round pricing. Hard to argue against, if you like the shape.

On shape for lab-grown: unless you specifically want a fancy shape, round at $235 median is the straightforward choice. The cushion premium at $361 needs a strong personal preference to justify at this price level.

Where to dig into the numbers

The full pricing picture for 0.5ct stones is at /insights/carat/0.5. Natural round detail at /insights/natural/round/0.5ct.

Lab-grown supply at this size is substantial: 302,977 stones in active listings. That depth keeps prices compressed. The current median of $259 is likely close to a structural floor given supply levels and current production economics. For anyone waiting for further drops, the marginal gains from here are small.

Natural half carats at $995 median have held steadier than larger sizes. One point three million stones in active listings is a genuine, liquid market. The G VS2 natural at roughly $1,020 and the D VS2 lab-grown at roughly $253 are the two reference points worth keeping. Any price meaningfully above those marks needs a clear reason from the stone's specs or cut quality. Any price meaningfully below them is worth scrutinising.