Dangling The One Carat Diamond Carrot

Online searches for one carat diamond rings are the highest of all the phrase terms we see when reviewing our website traffic.

This may come as no surprise. After all, a two carat diamond of even a medium colour and clarity grade is beyond most people's budget, while  "0.90 carat diamond ring" is not an instinctive search phrase.

Unquestionably, a one carat stone represents both a substantial and well proportioned size for any style of diamond ring.

But there are a couple of things worth considering in reaching your buying decision when it comes to diamond carat weight.


The surface diameter - or "face-up size" - of a round or princess (square) cut diamond does not increase in a linear fashion in accordance with carat weight.

For example, a one carat round brilliant cut diamond will have a diameter of between 6.2 and 6.7 mm. The diameter is determined by table and depth ratios which differ for each diamond.

In comparison, the diameter of a 0.90 carat (or "90 point") stone will usually be between 6.0 and 6.3 mm.

So, if it's diameter you are after, a well proportioned one carat diamond will only be around 5% greater on average than the smaller solitaire cited in this example.


No matter what your budget, both price and maximising value are bound to play key roles in your decision making process.

There are various ways to help maximise your budget and get the ideal ring without compromise. With this in mind we have compiled a quick guide which you may find useful.  See Guide

In the context of the size of a solitaire diamond more specifically, the typical variation in price in relation to carat weight is also non linear.

This tends to be particularly true in the case of a natural earth diamond which is exactly one carat weight and one which is very slightly less.

On the assumption that both diamonds are of commensurate grading (for example colour F, clarity VS2 with excellent cut and similar advanced characteristics), the price difference may surprise you.

Rather than the one carat stone commanding a price of around 10% more than the 90 pointer as one might logically expect, it will typically be more like 30% to 40% dearer.

The reason for this disparity in price is simply down to the usual forces of supply and demand.


There are numerous other aspects to consider in choosing your perfect diamond ring.

However, when it comes to diamond size at least, a little less weight can cost you a lot less money.