When choosing an oval lab-grown diamond, carat weight is often one of the first details to consider. From a dainty 1ct oval to a statement 4ct stone, carat can have a significant impact on the overall presence of your engagement ring.
But carat weight is only part of the picture. Two oval diamonds of the same carat weight can appear quite different depending on their length, width and ratio. In this guide, we explore how oval diamonds can vary across carat sizes, as well as how ratio influences the shape and proportions of your stone.
Carats
Carat is simply how much a diamond weighs. A carat is defined as 200 milligrams, and each carat is subdivided into 100 ‘points’. With all else of The 4Cs being equal, diamond price increases with diamond carat weight because larger diamonds are rarer and more desirable.
Two diamonds can have the same carat weight yet appear noticeably different on the hand, depending on their dimensions, proportions and how that weight is distributed.This is particularly noticeable with oval diamonds, where a longer or wider shape can create a different visual footprint on the finger.
For example, a 1.50ct oval may appear longer and more elongated than another 1.50ct oval, despite weighing exactly the same. Likewise, two ovals with similar dimensions can have different carat weights depending on their depth.
When comparing oval diamonds, it can therefore be helpful to look beyond the carat number and consider the stone’s actual measurements in millimetres. This gives you a clearer idea of the diamond’s face-up size and how it may present in an engagement ring.
For reference, the visual guide below shows how oval lab-grown diamonds can vary across different carat weights. While carat provides a useful starting point, the proportions of each individual stone will influence its final appearance.
Ratios
When designing your forever ring, every detail matters, and that includes your diamond’s ratio. While often overlooked, gemstone ratios are essential to the overall look and feel of your lab-grown diamond. The ratio refers to the length divided by the width of the stone, and it plays a key role in how your diamond appears on the hand, whether more elongated, perfectly balanced, or softly compact.
Though the difference between ratios might seem subtle at first glance, they can have a meaningful visual impact. Choosing your desired lab-grown diamond ratio can add a beautiful layer of personalisation to your engagement ring.
We know that pictures often speak louder than words, which is why we’ve created visual guides to help you better understand how each ratio presents across some of our most beloved lab-grown diamond cuts.
Oval diamonds are adored for their soft curves and graceful silhouette. Depending on the ratio, the same shape can appear more rounded and classic, or longer and more slender, offering a beautifully elongated effect on the finger. Pictured is a range from 1.25 to 1.60.
Finding Your Oval
At TMC, we look beyond the carat number, considering the diamond’s face-up dimensions and spread to select a beautifully proportioned stone. When we source a diamond, we consider carat weight, dimensions, spread, ratio and cut quality together. Through our signature process, we help you find the balance between visual presence, proportion and budget, rather than choosing by carat weight alone.
There is no single carat weight or ratio that defines the perfect oval. The right combination comes down to the proportions you are drawn to and how you want your diamond to present on the hand.
If you love a softer, more rounded oval, you may prefer a lower ratio. If you are drawn to a longer, more elongated silhouette, a higher ratio may be more suited to your style. From there, carat weight and millimetre dimensions can help you determine the overall presence you want your stone to have.
Ultimately, choosing your oval is about finding the balance between shape, size and proportion that feels right for you. Our jewellery consultants can guide you through different carat weights, dimensions and ratios, helping you compare each option during a one-on-one consultation. Or, we invite you to explore different diamond shapes, carat weights and proportions through our Signature Range online.
Learn more about Our Lab-Grown Diamonds.
