by Kunal Mehta

The Secret Behind Diamond Ratios : oval, marquise, cushion, old mine

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When you imagine your perfect diamond, chances are you’re picturing the sparkle, the size, maybe even the shape. But here’s something many people don’t realize until they’re actually shopping: the length-to-width ratio is what makes the diamond look more elongated or balanced and should be a top priority when selecting any diamond shape besides round.

And because every shape has its own sweet spot, understanding ratios can help you choose a diamond that looks just right on your hand. Let’s break it down by the shapes you’ll actually be deciding between.

Oval: Classic With a Twist

Oval diamonds are known for their elegance, but they can lean either wider or more stretched depending on ratio.

  • Sweet spot: 1.40–1.50
  • What it means: Lower numbers give you a softer, rounder oval; higher numbers elongate the stone and slim the finger.
  • Watch out for: The “bow-tie” shadow that shows up in the middle of some ovals. The right ratio helps balance sparkle with shape.

TikTok @thejewelstandard - https://www.tiktok.com/t/ZP8A3esX1/

Marquise: Drama at Your Fingertips

The marquise is all about length and drama, with its pointed tips that make your fingers look longer.

  • Sweet spot: 1.90–2.10
  • What it means: Around 2.0 is the classic marquise look — long and elegant without looking too narrow.
  • Watch out for: Extra-high ratios can make the stone feel more “needle-like,” while lower ratios start to look stubby.

TikTok @s.sxhxrr - https://www.tiktok.com/t/ZP8A3RN1X/

Cushion: Soft, Romantic, and Versatile

Cushion cuts are beloved for their vintage feel and soft corners.

  • Sweet spot: 1.30–1.45 for elongated, or near 1.00 if you prefer a square look
  • What it means: The choice comes down to personality — square feels timeless, elongated feels modern and slimming.
  • Watch out for: Cushion faceting styles vary a lot. Always look at the stone in person (or video) rather than relying on numbers alone.

TikTok @wundercut - https://www.tiktok.com/t/ZTMHUpGAG/

Old Mine: Vintage Charm

Old Mine cuts aren’t about perfection — they’re about personality. Hand-cut in the 18th and 19th centuries, they often have chunkier facets and higher crowns.

  • Sweet spot: There isn’t one! Old Mines vary wildly, often with ratios between 1.10 and 1.50. It really comes down to the look you are going for!
  • What it means: 1.3+ will offer the more elongated look, while 1.10 to 1.20 will be more balanced or squarish 
  • Watch out for: Old mine diamonds are made with a variety of faceting styles that you will immediately notice when looking at the stone. Look at a couple of options to find the one that speaks to you!

TikTok @ericasett - https://www.tiktok.com/t/ZTMHUf6tN/

These shapes — oval, marquise, cushion, and old mine — each have their own character and romance. The right ratio helps bring out that personality while complementing your hand shape.

If you’re drawn to the timeless, feminine side of diamond design, these may be your perfect starting point.

Curious about pear, emerald, or radiant diamonds? Read more in our blog post