Collection of popular lab-grown diamond shapes including round, oval, and emerald cut

Most Popular Diamond Shapes in 2026-2027

Shape is the decision that quietly determines everything else, how the ring looks on the hand, how big it reads next to its actual carat weight, even how it catches light walking into a room. In the US and Canada, couples still lean classic, but the fancy shapes are closing the gap fast. Here's what's actually popular right now, and why, if you're eyeing a lab-grown diamond engagement ring.

Quick Takeaways

  • Round brilliant is still the most chosen shape for engagement rings: 28% of respondents have a round gem in The Knot's 2024 Jewelry and Engagement Study.
  • Oval is a close second at 25% in the same study, helped by the way it looks bigger than its actual carat weight and flatters many hand shapes.
  • Princess and emerald remain steady favorites for anyone who wants clean geometry over maximum sparkle.
  • Want the technical side? See GIA's 4Cs and IGI's lab-grown diamond report guide.

The Shapes, One by One

1) Round Brilliant

Round earns its reputation honestly. Maximum light return, endless styling options from clean solitaires to full halos, and it never goes out of fashion because it was never really "in" fashion to begin with, it's just correct. Learn how cut affects brightness in GIA's cut guide.

4 carat round brilliant lab-grown diamond engagement ring

2) Oval

Oval gives you finger-lengthening elegance and a bit of an optical illusion, it faces up bigger than round at the same carat. Pairs beautifully with minimal solitaires and micro-pave halos alike. Compare current preferences in The Knot study, then browse our solitaire ring collection, including a 5 carat lab grown oval diamond ring if you're sizing up.

3 carat oval cut lab-grown diamond solitaire engagement ring

3) Princess

Crisp corners, lively sparkle, a distinctly modern silhouette. Princess pairs well with channel-set bands and sleek solitaires alike. For background on diamond properties, see GIA's diamond encyclopedia.

4) Emerald

Emerald plays a different game entirely. Its step facets give you a hall-of-mirrors glow instead of a glittery burst, which is exactly why it draws people who want elegance without shouting about it. Pair it with a thin pave band or tapered baguette sides for the full effect.

4 carat emerald cut lab-grown diamond engagement ring

5) Cushion

Rounded corners soften the square outline, delivering romantic sparkle that shines in vintage and halo designs especially. See IGI's lab-grown diamond report page for certification guidance.

6) Pear

The teardrop silhouette is unmistakable, elegant pointed up the finger and slightly elongating for the carat weight. Setting security at the tip matters more here than on most shapes.

Pear cut lab-grown diamond halo engagement ring

7) Marquise

Marquise stretches for maximum length and a bold, vintage-leaning presence, one of our most requested marquise diamond ring styles for buyers chasing a distinctive silhouette. Prong coverage at the tips matters here too. Browse elongated styles in our engagement ring collection.

8) Radiant, Asscher, Heart, and the Rest

Radiant blends a rectangular outline with brilliant faceting. Asscher is a vintage square step-cut with real architectural presence. Heart is exactly what it sounds like: playful, symbolic, not for everyone but beloved by the people it's for. Explore specialty shapes in our rings collection.

What This Means If You're Shopping Lab-Grown

Lab-grown diamonds make it much easier to size up without compromising on quality, and in overall engagement ring surveys round and oval lead, with other shapes well behind. Don't forget metal matters just as much as shape: see our gold vs. plated jewelry guide before you commit.

Buying Checklist

  1. Start with cut quality, it drives the sparkle more than anything else. See GIA cut.
  2. Balance color and clarity for the shape and setting you've chosen.
  3. Confirm independent certification on every diamond, no exceptions.
  4. Compare face-up dimensions, not just carat weight, especially with ovals and emeralds.
  5. Check current price per carat before you set a budget.

Engagement Rings: The Shapes Heading Into 2027

Round brilliant still leads the pack in the US, but its lead over oval is narrow:

Shape The Knot 2024 Jewelry and Engagement Study The Knot 2023 Real Weddings Study
Round Brilliant 28% 34%
Oval 25% 23%
Pear Not reported 8%
Princess, emerald, cushion, marquise, radiant, Asscher, heart Smaller shares; not broken out in these summaries

Sources: The Knot 2024 Jewelry and Engagement Study and The Knot 2023 Real Weddings Study, as reported by JCK.

With affordability on buyers' minds, lab-grown diamonds now make up the majority of US engagement ring purchases: lab-grown center stones account for 61% in The Knot's 2026 Real Weddings Study. Curious what that actually costs? See our lab-grown diamond price guide.

Frequently Asked Questions

What's the most popular diamond shape right now?
Round brilliant, though only narrowly: 28% versus 25% for oval in The Knot's 2024 Jewelry and Engagement Study.

Does shape affect how big a diamond looks?
Yes, significantly. Oval, marquise, and pear all face up larger than their actual carat weight, while round and cushion tend to look closer to their true size.

Is one shape more durable than another?
Pointed shapes like marquise and pear have more vulnerable tips and need secure prong coverage. Round and cushion are the most forgiving for everyday wear.

Are unique shapes harder to find in lab-grown?
Not anymore. Lab-grown production has made even less common shapes widely available and often more affordable to customize than natural stones.

Shop by Shape

Not every shape needs to be a solitaire either. The Evolution Ring lets you change shape and color in one setting, and our colored diamond engagement rings cover fancy-color stones for anyone who wants something beyond classic white. Shopping for engagement rings for men? See our men's lab-grown diamond jewelry. Ready to find your shape? Shop our lab-grown diamond engagement rings.

Sources

Shop Lab Grown Diamond Jewelry

Browse our most popular collections: 3 carat lab grown diamond rings, 2 carat lab grown diamond rings, 4 carat lab grown diamond rings, 5 carat lab grown diamond rings, lab grown diamond tennis bracelets, lab grown diamond stud earrings, lab grown diamond wedding bands, rose gold engagement rings, lab grown diamond engagement rings and lab grown diamond necklaces. Every piece is IGI certified and ships free to Canada and the United States.

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