Diamond Price by Carat, From 0.5ct Through 5ct With Live Bands

The jump from a 0.90ct to a 1.00ct round diamond isn't a 10% price difference. Across our index of 14 million stones, it's closer to 40%. That fact about diamond price by carat explains why so many buyers arrive at a budget and leave confused about why the stones they liked cost so much more than expected.

Our pillar on how much a 1 carat diamond costs covers the full framework, including how cut, colour, and clarity interact with weight to set market value. This post is the reference you come back to: what round brilliants cost across the weight spectrum, natural and lab-grown side by side, and where the real price steps fall.

The benchmark throughout is G VS2 Excellent cut for round brilliants. That spec represents the most popular quality tier for engagement ring buyers: genuinely beautiful, consistently eye-clean, well-cut enough that the stone performs in any lighting. Using one fixed quality point means prices are directly comparable across weights.

Two markets with different pricing logic

Natural and lab-grown diamonds aren't priced by the same forces. Understanding the diamond price chart by carat weight means understanding that you're really looking at two separate curves, not one.

The lab-grown vs natural price spread has been widening for years. At the 1ct mark, natural round brilliants run at roughly 7.6 times the price of lab-grown equivalents. At 2ct, that ratio is closer to 15 times. Above 2.25ct, natural medians are running at more than 24 times the lab-grown median.

Same shape. Same cut grade. Radically different pricing logic.

Prices by weight

The figures below are median prices from our active index, separated by origin. Per carat estimates use the band midpoint as the denominator. These are medians across all grades for round brilliants; G VS2 Excellent stones sit toward the upper portion of each band. The 2.25ct and above row covers a wide spread of weights, so treat that figure as a market entry point, not a precise target.

Weight band	Natural median	Natural per carat	Lab median	Lab per carat	Nat/Lab ratio
Below 0.75ct	$644	~$1,290	$253	~$510	2.5x
0.75 to 1.24ct	$2,734	~$2,730	$360	~$360	7.6x
1.25 to 1.74ct	$6,148	~$4,100	$560	~$370	11x
1.75 to 2.24ct	$12,348	~$6,170	$802	~$400	15.4x
2.25ct and above	$32,010	varies	$1,318	varies	24.3x

The natural per carat column tells the story of rarity compounding. Per carat cost roughly doubles from the lightest weight band to the 1ct range, then climbs another 50% into the 1.5ct range, then another 50% to 2ct. Each weight threshold you cross costs progressively more per unit of diamond than the last.

Lab-grown runs differently. Per carat cost in the lightest band is roughly $510. At 2ct, it's closer to $400. The curve is nearly flat and slightly downward. You're not paying a rarity premium at each new weight threshold because there isn't one.

Where the real cliffs are

Magic size premiums are real. The advice about buying a 0.98ct instead of 1.00ct is not wrong. But the biggest price cliff in the natural market isn't at exactly 1.00ct. It's at 0.75ct.

A natural round below 0.75ct has a median of $644. Cross into the 0.75ct to 1.24ct range and the median jumps to $2,734. That's 4.25 times the price for a band that starts at just 0.75ct. You don't need to reach 1.00ct to feel that cliff. Crossing 0.75ct is enough.

From there, the steps are steep but more consistent. The 1ct band to the 1.5ct band is a 2.25 times increase. From 1.5ct to 2ct, another 2 times. From 2ct into the 2.25ct and above band, the median leaps to $32,010. That's 2.6 times the 2ct median for a weight increase that, visually on the hand, most people couldn't identify in a blind test.

For lab-grown, these cliffs exist at nothing like the same scale. Band to band increases run 40 to 65%. Those are real steps, but they're not the multipliers that define natural pricing. A lab-grown buyer weighing up 1.8ct versus 2.00ct faces a genuinely different decision than a natural buyer making the same comparison.

Where natural buyers find room

The natural price per carat curve is steep and consistent. Two things follow from that.

Staying just below a weight threshold matters more than many buyers expect. A well-cut 0.90ct G VS2 looks almost identical to a 1.00ct on the hand. The visual difference is small; the price difference sits at roughly 40%. The same logic applies at 1.45ct versus 1.50ct, and again at 1.90ct versus 2.00ct. These aren't trivial savings. At the 2ct threshold, sitting at 1.90ct means staying inside the 1.75ct to 2.24ct band at a $12,348 median, rather than crossing into territory where the median is $32,010.

Within each band, there's also meaningful variation. Our index at the 1ct band alone carries over 276,000 active natural round listings. The spread between the cheapest and most expensive comparable stones at similar specs is wide, and not all of that spread reflects quality differences. Retailer pricing strategies differ significantly. Searching by specific parameters rather than browsing by carat alone is where buyers consistently find better value.

Lab-grown at the larger sizes

The flat per carat curve for lab-grown reflects production economics rather than rarity. Growing a larger crystal costs more, but not exponentially more. The scarcity premium that makes natural pricing compound at each weight threshold has no equivalent in a lab environment.

For buyers open to lab-grown, the weight decision is genuinely different. Choosing between 1.5ct and 2ct in natural means crossing from a $6,148 median to a $12,348 median: a near doubling of the investment for a stone that's measurably, but not dramatically, larger. The same choice in lab-grown takes you from $560 to $802. That 43% increase buys a stone that's roughly a third wider in diameter and noticeably more present on the hand.

At the 1ct level, there are over 594,000 lab-grown round listings in our index. That depth of inventory means buyers have real choice on spec: selecting the best cut within a quality tier rather than settling for what happens to be available. At 2ct in natural, the 53,729 listings in the 1.75ct to 2.24ct band offer far less room to move.

The 2.25ct and above band is where the calculation becomes most stark. A natural stone in that tier has a $32,010 median. Lab-grown in the same tier sits at $1,318. For buyers who want a genuine statement stone and aren't prioritising resale value or natural provenance, that 24 times gap is hard to look past.

Beyond the round brilliant

Everything above covers round brilliants, the right shape for a benchmark spanning both markets. Rounds carry the deepest liquidity in natural and in lab-grown: over 276,000 active natural listings at the 1ct band, over 594,000 lab-grown in the same range. Pricing signals are clearest where inventory is deepest.

Other shapes follow broadly similar patterns but with different base prices. Natural ovals track close to rounds at the 1ct band, with a $2,560 median versus $2,734 for rounds. Natural emerald cuts run slightly below rounds in the lower weight bands but above them at 2.25ct and above, where the emerald median sits at $36,155 compared to $32,010 for rounds. Lab-grown ovals in the 2.25ct and above band carry 425,752 active listings in our index, more than any other shape in that tier. The sheer volume of lab-grown stock at larger sizes tells you something about where supply has landed.

The diamond carat weight guide covers how physical dimensions vary by shape at the same stated weight, which matters a great deal when you're comparing an oval and a round at 1.5ct and wondering why they look so different on the finger.

What we're watching

Natural prices above 2ct have been holding firm in 2026. The 2.25ct and above natural round median of $32,010 reflects a market with no meaningful softening at the top end. Lab-grown in the same tier, at $1,318, reflects significant supply pressure; production capacity for larger lab-grown stones has expanded well ahead of consumer demand, and that compression shows no sign of reversing.

The weight where this plays out most interestingly for buyers right now is 1.5ct. An 11 to 1 ratio between natural and lab-grown medians at that weight is historically wide. Buyers who would have dismissed lab-grown two years ago are reconsidering the spec at 1.5ct in a way they weren't before. The natural premium at that weight is real; whether it's worth eleven times the price is a question more buyers are choosing to answer for themselves.

If you're approaching 2ct in natural, the conversation worth having is whether the spec can sit just below 2.00ct. A well-cut 1.90ct G VS2 round looks almost identical to a 2.00ct. That 1.90ct sits inside the 1.75ct to 2.24ct band at a $12,348 median. A stone at 2.25ct and above starts at $32,010. That's the real 2ct cliff, and the data on diamond price per carat in 2026 is clear about exactly where it begins.