Diamond Carat Buying Guide: Does Size Matter?

The word Carat came from the carob seed (carob is a bean that is a substitute for chocolate), and this seed was used a measurement of weight before the 19th century. A carob seed weighs was roughly .20 grams (or about .007 ounces) which is exactly the weight of a 1carat diamond. 

The carat is used universally, so you can buy a diamond in any country and they’ll use the same terminology. No tricky calculations like trying to figure out what the temperature is in Fahrenheit when it’s Celsius. Enough of the history lesson, lets get into what you really came for. You want to know if you’re buying a diamond, do the number of carats matter? Let PhD answer for that you. 

Does Size Matter?

I mean that’s what we are really asking. WIth 1/100th of a carat able to make the difference of hundreds or thousands of dollars, I hate to say this – but it does. Even though the price of a diamond is determined by all of the 4 C’s of the diamond – carat, cut, clarity, and color, ultimatley the price is calculated based on the actual carat weight.  

Take a look at the chart below, which tells you the ‘price per carat’ for round shaped diamonds at different weight classes. The price is in $100s, so a VS1 ,D colored, 2 carat diamond will cost says 290 per carat, which means its $29,000 per carat or ($58,000 for 2 carats). So basically the formula to calculate the price of your diamond is: 

Diamond Price = price show x # of carats x 100Image result for rapaport price list 2018


If you study this report, you’ll see that a 1.99 carat D colored, vs1, round diamond will cost $35,230 (177 x 1.99 x 100). That considerably less than the 2 carat diamond price for the same diamond which costs $58,000. You’re probably asking, how can that be? Well it is, and the reason behind that is scarcity. As you increase the number of carats in a diamond, the rarer they are to find – so the price increase is almost exponential! Keep in mind that the prices above are going to be higher than what you will find online because online diamond stores such as Blue Nile, James Allen, or Whiteflash offer diamonds prices at up to 40% lower than what you would find at a traditional brick and mortar retailer.

Tip: If you are looking for a diamond that looks like a full carat size (e.g. 1ct or 2ct) but want to pay a little less, consider going slightly below that carat number. So instead of a 1ct diamond, get a .97ct. or .98ct; or for a 2ct diamond, get a 1.97ct or 1.98ct diamond – you’ll save money.

Diamond Proportions

I think its important to get a sense of scale of a diamond, especially since it can be hard gauge when buying online. Look below to see how big diamonds actually are at different carat sizes and shapes.



How Big Will that Look on a Hand?

When it comes to carat weight, make sure that you are considering your budget AND what will look best. The picture below shows a great representation of different sizes on an average female hand

Consider what will look best in regards to the size of the hand that will be wearing the diamond and the overall cut of the diamond. The shape is a personal choice, but most information written about diamonds refers to the round cut because of its overall popularity.


PhD’s Conclusion

The appeal of a diamond’s shape is entirely in the eye of the beholder. Whether you choose a heart shape or a marquise, the most important aspect to consider is your happiness. Stay close to your budget, don’t mortgage the house just to buy the 10-carat diamond. 

The quality of the diamond and the way that it looks should be more important than the weight that is on paper. People will be looking at your diamond, not the paperwork, so make sure that it’s worth the glances that it will get. At the end of the day, if the diamond makes you smile when you look at it, it’s the right carat and you’ve chosen well!