Understanding Lab-Grown Diamond Carats: Size, Value & Tips

Diamonds have long been symbols of love, commitment, and celebration. But with the rise of lab-grown diamonds, more Australians are choosing this ethical and sustainable alternative. When buying a diamond—especially for an engagement ring—one of the most important factors to consider is the carat. In this guide, we’ll explain everything you need to know about lab-grown diamond carats, helping you make an informed and confident choice.

What is a Diamond Carat?

A carat is the standard unit of measurement for a diamond’s weight, not its size. One carat equals 200 milligrams (0.2 grams). The term comes from the carob seed, which was historically used as a reference due to its uniform weight.

However, it’s important to understand that carat weight is just one aspect of a diamond’s value. Two diamonds with the same carat weight can look very different in size, sparkle, and price depending on the cut, shape, and other factors.

Carat Weight vs. Carat Size: Know the Difference

Many people assume that a higher carat weight means a bigger diamond, but that's not always the case. While carat affects the size, the cut and shape of the diamond also significantly influence how large the diamond appears to the eye.

For example:

• A 1-carat round brilliant cut may appear smaller than a 1-carat oval or pear-shaped diamond because of how the weight is distributed.

• A diamond with a shallow cut may appear wider than one with a deeper cut of the same carat weight.

So, if you want a diamond that looks bigger, consider alternative shapes like oval, emerald, or marquise—especially with lab-grown options where budget goes further.

Lab-Grown Diamonds: Do Carats Mean the Same?

Absolutely. Lab-grown diamonds are real diamonds, both chemically and physically. Carat weight for a lab-grown diamond is measured the same as for a natural diamond. A 1-carat lab-grown diamond weighs exactly the same as a 1-carat natural diamond.

The key difference is how the diamond is created:

• Natural diamonds form over billions of years under the Earth’s surface.

• Lab-grown diamonds are created in a lab over a few weeks using advanced technology like CVD (Chemical Vapour Deposition) or HPHT (High Pressure High Temperature).

Because lab-grown diamonds don’t go through the traditional mining and supply chain, they can be 30% to 40% more affordable, allowing you to purchase a higher carat weight for the same price.

Popular Carat Weights for Engagement Rings in Australia

At Rings of Australia, we’ve seen a growing demand for lab-grown diamond engagement rings. Here are the most popular carat weights among our customers:

● 0.50 Carat Lab-Grown Diamonds

Perfect for minimalists or budget-conscious buyers. These diamonds are elegant and subtle while still providing beautiful sparkle.

● 1.00 Carat Lab-Grown Diamonds

The classic choice. A 1-carat diamond balances presence and affordability and is a timeless favourite for engagement rings.

● 1.50 - 2.00 Carats

For those wanting extra wow factor. A 1.5-carat or 2-carat lab diamond offers brilliance and boldness, ideal for statement rings.

● 2.5 Carats and Above

Rare in mined diamonds but far more accessible with lab-grown. Great for anniversary rings or those who want the ultimate showstopper.

How Much Does a Lab-Grown Diamond Carat Cost?

The price per carat varies depending on the diamond’s cut, clarity, and colour. Here’s a general breakdown of lab-grown diamond prices in Australia (as of mid-2025):

Note: These prices are estimates. For exact quotes, visit our product pages or request a custom consultation.

Carat Weight and Finger Size: Choosing the Right Fit

A diamond’s appearance also depends on your finger size. A 1-carat round diamond might look more prominent on a size 5 finger than on a size 8.

Here are some tips:

• Smaller fingers (sizes 4–5.5): 0.5 to 1.25 carats look proportionate.

• Medium fingers (sizes 6–7.5): 1 to 1.75 carats work beautifully.

• Larger fingers (sizes 8+): 1.5 carats and above create the perfect balance.

Our expert jewellers at Rings of Australia can guide you through choosing the ideal carat for both your style and hand.

The Sweet Spot: Balancing Carat with Cut and Clarity

When buying a diamond, it's not just about carat. The 4Cs—Carat, Cut, Clarity, and Colour—work together to determine overall beauty and brilliance.

Many of our clients choose slightly lower carat weights (like 0.90 instead of 1.00) to save money and allocate budget toward better cut or clarity, which often has more visual impact than an extra 0.10 carat.

Tip:

Always prioritise cut quality over carat if you want a diamond that sparkles brilliantly. A well-cut 0.90-carat diamond can often look better than a poorly cut 1.00-carat diamond.

Why Carat Weight Matters for Settings and Styles

The carat also influences the ring setting and overall style. Larger carat diamonds often require more secure settings and may not pair well with delicate bands.

Here are popular pairings:

• Solitaire settings: Perfect for showcasing diamonds of any carat weight.

• Halo settings: Make smaller diamonds appear larger.

• Three-stone rings: Ideal for showcasing a central diamond flanked by smaller side stones.

• Hidden halo or cathedral styles: Add dimension and visual size without increasing carat.

At Rings of Australia, all our rings are custom-crafted to suit the exact carat weight of your chosen diamond.

Sustainability and Value: A Carat That Cares

Choosing a lab-grown diamond means choosing sustainability. With growing awareness of ethical sourcing and environmental responsibility, more Australians are embracing lab diamonds as the modern, conscious choice.

By choosing a larger carat lab-grown diamond, you get:

• A luxurious size without the environmental cost

• Better value for money

• A transparent, traceable supply chain

FAQs About Lab-Grown Diamond Carats

1. Are lab-grown diamonds available in every carat size?

Yes! You can find lab-grown diamonds from 0.25 carat to over 5 carats. Custom orders are also available for specific sizes.

2. Will a lab-grown diamond of higher carat look different from a mined one?

No. Lab-grown diamonds are visually identical to natural diamonds. Only specialised equipment can tell them apart.

3. Do lab diamonds lose value because of carat?

Like all diamonds, lab-grown diamonds are not an investment asset. However, because they are more affordable, you can invest in a larger, more beautiful diamond for less.

4. What’s the best carat size for an engagement ring?

A 1 to 1.5-carat lab diamond is the most popular range, offering the perfect balance between size and budget.

Final Thoughts: Carat Clarity Starts with You

Understanding lab-grown diamond carats helps you make smarter, more confident choices when selecting your ideal engagement ring or fine jewellery piece.

At Rings of Australia, we specialise in ethically sourced, premium-quality lab-grown diamonds designed to suit every budget and style. Whether you're after a sparkling 0.5-carat for everyday elegance or a 2.5-carat showstopper for a once-in-a-lifetime proposal, we’re here to help you shine.

Ready to Choose Your Dream Diamond?

Explore our collection of lab-grown diamond rings by carat, cut, or style — or get in touch with our experts for a free consultation.

Rings of Australia – Where ethical luxury meets timeless beauty.