Let’s be honest: buying a diamond isn’t exactly something most people do every day. And if you’re planning a proposal, the pressure to “get it right” is real. One of the first questions that probably popped into your head? How big should the diamond be?
It sounds simple, but it’s not just about picking the biggest stone your budget allows. There’s a bit more to it—like how carat weight works, how it affects price, and what actually looks best on her hand.
Let’s clear it all up.
First Things First, What Even Is Carat Weight?
Carat weight refers to how much a diamond weighs. It’s measured in metric carats, where 1 carat equals 200 milligrams. That’s about the weight of a paperclip.
But here’s where people often get confused: Carat weight isn’t the same as how big a diamond looks.
It’s easy to assume that a higher carat means a larger diamond—and yes, to a degree, it does. But there’s more going on. Two diamonds can weigh the same and still look very different depending on how they’re cut and shaped.
So Then… What’s “Diamond Size”?
When people say “size”, they’re usually talking about the face-up appearance—the top view of the diamond when it’s set in a ring.
This is where shape and cut really come into play. For instance, an oval or marquise diamond tends to look larger than a round diamond of the same weight, simply because of how it stretches across the finger. Meanwhile, a deeper-cut diamond might carry more weight below the surface, which you won’t see.
So, yes—carat matters. But if you’re going for visual impact, how the diamond is cut and shaped might matter more.
Carat and Price, Where the Big Jumps Happen
Let’s talk money for a second.
You’ve probably noticed that prices jump a lot at certain carat weights—like 0.5ct, 1ct, 1.5ct, and 2ct. These are known in the industry as “magic numbers”. Even a tiny increase that takes you from 0.98 to 1.00 carat can come with a hefty price hike.
The funny thing? Those two diamonds may look nearly identical to the naked eye.
That’s why many buyers go just under these thresholds—say, a 0.91ct instead of a 1.00ct—to get more value without sacrificing appearance. It’s a clever move that can make a real difference in what you can afford overall.
What Carat Weight Do Most People Go For?
There’s no single answer here. A “perfect” carat weight doesn’t exist—it’s personal. That said, here’s a general feel for what many people choose:
- 0.3ct – Ideal for petite hands or those who prefer a delicate, understated look.
- 0.5ct – Great for minimalists or lovers of vintage-inspired rings.
- 0.7ct – A popular sweet spot that looks balanced on most finger sizes (especially Japanese sizes 8–11).
- 0.9ct – Offers the best cost-performance ratio: noticeable sparkle without a steep price jump.
- 1.0ct and above – Makes a statement. Perfect if you want standout brilliance, especially when paired with a bold setting.
But remember, hand size changes perception. A 1-carat diamond can appear quite large on a Japan size 6 finger, but more balanced or modest on a size 12. Also, the band matters. A slim band can make the diamond look bigger; a chunky one might make it seem smaller.
Not All Carats Are Equal, Cut Really Matters
Here’s the thing most first-time buyers miss: a well-cut diamond will always shine more than a heavier one with a poor cut.
Why? Because the cut controls how light travels through the stone. A poorly cut diamond might leak light out of the sides, making it look dull and lifeless, no matter how big it is.
That’s why going for a Triple Excellent Cut—which means top marks for cut, polish, and symmetry—is such a smart move. It makes sure your diamond shines brilliantly from every angle.
So if you’re on a budget, choosing a slightly smaller diamond with a Triple Excellent Cut usually gives you more sparkle and wow factor than a larger diamond with a lower cut grade. And really, isn’t that what you want?
Want It to Look Bigger Without Paying More?
Good news—there are tricks.
Here’s how to make a diamond look bigger, even if you’re staying under a certain carat weight:
- Go with a halo setting. It surrounds the centre stone with smaller diamonds, which adds sparkle and size without pushing up the budget too much.
- Stick to a thin band. The slimmer the ring, the bigger the centre stone appears by comparison.
- Consider a bezel or flush setting. It adds visual width and brings more attention to the stone itself.
What About Clarity and Colour?
It’s easy to get caught up chasing the highest specs across all four Cs (cut, colour, clarity, carat). But unless you’re buying with a magnifying glass in hand, there’s room to compromise.
For most people, clarity isn’t a huge issue as long as there are no visible flaws. A slightly lower clarity grade can save you money, especially if the blemishes are on the sides or under the setting.
Colour is more noticeable in certain shapes. Round diamonds tend to hide colour better than step cuts. So if you’re considering a more geometric cut, you might want to lean towards a higher colour grade.
Again, it’s about balance, not perfection.
What She Really Wants (Hint: It’s Not a Number)
Here’s something worth thinking about: most people can’t tell the difference between a 0.90ct and a 1.00ct diamond without a jeweller’s loupe.
What really stands out? The sparkle. The setting. The fact that you picked something with her in mind.
Look at what she wears now. Is it simple or bold? Does she like gold or platinum? Classic or modern? These hints will guide you more than any chart ever could.
Why I-PRIMO Makes It Easier
With over 200 styles and countless diamond options, I-PRIMO doesn’t just sell rings—we help people find the one that fits their story.
Whether you’re after a dainty solitaire or a showstopper with a full halo, we’re here to walk you through it. You can compare shapes, test out sizes, and get real answers from people who actually know what they’re talking about.
We get it, this is a big moment. And it deserves a ring that feels just right.
Check out our diamond engagement ring collection or book a consultation to get started.
The Bottom Line: Bigger Isn’t Always Better
Sure, size matters—but it’s not the only thing that does. A well-cut diamond, a flattering shape, and a setting that complements her style can all make a ring feel more special than just chasing numbers on paper.
The best diamond isn’t the most expensive one in this case. It’s the one that fits your budget, suits her style, and feels like you put real thought into it.
And that, more than any carat weight, is what makes a ring unforgettable.
