Celebrating moms all month. Use code MOM15 for 15% off earrings & necklaces.

Lab Diamond Carat Guide

Sparkly and beautiful, its little wonder diamonds are so desirable. Lab-grown diamonds are very popular and it’s easy to see why - they are striking and affordable. The 5-carat diamond price of a lab diamond is far less than the 5-carat diamond price of a natural diamond. However, both have the same chemical attributes and look identical.

In this guide, we’ll explore diamond carat size in more detail (from the 1-carat diamond to the 5-carat diamond). We can’t promise you’ll be a diamond expert by the end, but you’ll certainly know more about the coveted gemstones,


What is Diamond Carat?

Diamond carat does not relate to diamond sizes, but weight. The diamond carat size is the unit of measurement used to define how heavy the gem is. To put this in context a 5-carat diamond size would weigh more than a 3-carat diamond size.


The Origins of The Diamond Carat System

Carat weight was originally calculated using carob seeds. Traders used the seeds as counterweights to balance their scales. Nowadays actual carat size is calculated in the same way across the globe and all diamonds are weighed using identical milligram weights to ascertain carat size.


Calculating Lab Diamond Carat Weight

Each metric carat weighs 200 milligrams and every carat is segmented into 100 points, allowing for accurate mensuration. A gem below a 1-carat diamond size is often defined by its points.

Here’s an overview of the carat measuring unit system:

  • 0.5 carat = diamond 0.1 grams / 0.0035 ounces.
  • 1 carat diamond = 0.2 grams / 0.007 ounces.
  • 2 carat diamond = diamond 0.4 grams / 0.013 ounce.

Jewelers often use a carat size chart for easy comparison and you might hear them discuss “carat points” too. For instance:

  • 0.60-carat diamond = 60 points (0.120 grams)
  • 1.40-carat diamond = 140 points (0.28 grams)
  • 2.18-carat diamond = 218 points (0.436 grams)

Carat Size Vs Actual Size of the Diamond

We’ve already mentioned that diamond carat relates to the weight of the diamond, rather than its size. However, carat size provides an indication of how big the diamond looks when viewed from the top. A 5-carat diamond engagement ring will boast a larger diameter, topmost crown, or table than a 3-carat diamond engagement ring.

Measurement of Round Shape Diamond Carats

Round diamonds are very popular, but they are also the most expensive of all shapes. There are a couple of reasons for this, first off a round diamond has multiple facets. This makes it more difficult to cut and approximately half of the original diamond will be cast aside.

The popularity of the round cut also pushes the price up. A round-cut diamond costs approximately 25-35% more than another shape sharing the same weight, color, and clarity. So, if you’re looking to invest, a round cut is perfect, however, a 1-carat diamond engagement ring won’t do, go for a 5-carat diamond.


Diamond MM Chart


carat size chart with round diamonds showing the millimeter size of each popular diamond size


Does Carat Impact the Cost of the Diamond?

The general rule of thumb is the higher the weight (carat size), the higher the price. Tiny differences in carat weight can alter the price by massive margins, depending on the quality and size of the gem

Diamonds boasting a greater carat weight, such as a gem you’d find in a 5-carat diamond ring, are typically cut from bigger, coarser crystals. The price of a diamond reflects its rarity, so a diamond cut from a rare rough crystal will be more expensive.

Again, the price isn’t linear, so a 3-carat diamond price won’t be three times more than a 1-carat diamond price, and a 4-carat diamond price won’t be double a 2-carat diamond price. We should also remember that carat size isn’t the only factor, other elements come into play too, such as clarity, color, and cut.


How Important is Carat Compared to the Other 4 C’s?

The 4C’s are carat, clarity, cut, and color. Carat size plays a part in determining the price and quality of a diamond but bigger isn’t always better. A larger carat such as a 4-carat diamond size could have an inferior cut, and a lower carat, such as 3-carat diamond ring could boast a quality cut that makes it look better and brighter.

Shaped diamonds are ideal if you want to draw attraction to your gem. Rectangles, ovals and marquise stones will give the illusion that your diamond is larger than its carat weight. The setting also affects the appearance of your ring – a halo or bezel setting will enhance the size of the stone.


What Carat Diamond Should I Choose for an Engagement Ring?

A 1-carat diamond ring has proved to be an inherently popular choice for marriage proposals, but recently loved-up couples have had their heads turned by gems boasting around 1.50 carats.

Of course, you can go for a higher carat and opt for a 2-carat diamond size, a 3-carat diamond, a 4-carat diamond, or even a 5-carat diamond (if you can afford the 5-carat diamond price). Some worry that a larger carat will prove to be too heavy in terms of carat size on hand, but it’s not the gem that makes the ring feel weighty, it’s the metal setting.


Round Diamond Carat sizes: .25, .50, .75, 1.00, 2.00, 3.00, 4.00, and 5.00 cts on hand

Best Carat Diamond Sizes for Rings, Earrings, and Necklaces

Diamonds aren’t just for engagement rings – a diamond ring will really stand out. Choose a carat size to complement your hands, and fit your lifestyle. If you have stouter fingers a larger carat size e.g., a 4-carat diamond ring might suit you well.

However, you should also think about your lifestyle, if you’re active and work in a manual job a 2-carat diamond ring should be big enough to show off and wear without worry.

Diamond earrings and necklaces look stunning too. Don’t forget the carat size is split between both earrings. You can opt for a smaller carat (ideal for work or play), or go for something a little grander. Anything more than 1.25 carats is going to be a little more expensive.


FAQ

We’ve given you the lowdown on diamond carats, now let’s check out a few frequently asked questions on lab diamond carats:

What is Carat Weight?
Is Carat Weight the Same as Diamond Carat Size?
Does a Bigger Carat Size Equal a Bigger Diamond?
What’s the difference between Carat and Karat?
Fill out my online form.