Breaking Down Diamond Ratios and Popular Cuts

There are a number of factors that are important when you’re considering a diamond ring purchase, from the simple shape and appearance of a stone or band to details like the precise cut, clarity, or even various measurements. And when it comes to the latter areas, one of the factors that’s sometimes underplayed during the buying experience is known as diamond ratio.

Also called length-to-width ratio, this basic assessment of a diamond’s proportions is often a very important element in determining the final price of your ring. We’re happy to help with diamond ratio for all our engagement and wedding rings at AAA Jewelers – let’s go over what it means and how it’s calculated, plus break down the common ratios you’ll generally find in some of the more popular diamond cuts available today.

Defining Diamond Ratio

Diamond ratios are defined in millimeters, and the calculation for determining them is extremely simple: Find the length of the diamond, then divide it by the width. As a very simple example, a diamond that’s 11mm long and 8mm wide will have a ratio of 1.375, though some jewelers may choose to round up to tenths and label this 1.4 instead (the technically correct expression is 1.4:1, but the first number is often listed alone to save space).

Once you have this number, you have a general definition for the overall shape of the diamond. A perfect square diamond, for instance, will have a ratio of exactly 1.0, as it is evenly long and wide. Most other cuts, however, will have different and larger ratios – our next section will go over some standard ratios found in the kinds of cuts you’ll see at most jewelers today.

Popular Ratios for Various Cuts

• Oval cuts: Oval diamonds are among the longer options out there, and this means it tends to come with relatively high ratios. You have a range of choices available here – ratios in the 1.3 to 1.35 range will be a bit shorter, while anything above 1.4 or so will look thinner and a bit more slender. It’s somewhat unusual to see oval cuts with a ratio over 1.5, though it’s possible.
• Radiant cut: Radiant cuts can come in a huge range of options, from squares with virtual 1.0 ratios all the way to elongated cuts with ratios of 1.3 and higher. Know that longer diamonds will take up more space on your finger.
• Cushion cut: Also available in a range, but with a lower general cap on ratios. You generally see cushion cuts in the 1.0 to 1.15 range.
• Emerald cut: These are similar to radiant cut diamonds, but with some designs that reach ratios of even 1.5 or 1.6 in some cases.
• Pear cut: Pears are on the rise recently, with high ratios in the 1.4 to 1.6 range.

For more on diamond ratios, or to learn about any of our engagement rings or other jewelry options, contact the pros at AAA Jewelers today.