3 Carat Diamonds

To showcase your love in lustrous fashion, shop the selection of 3 carat diamonds available at Blue Nile. These large, loose diamonds make a dazzling, dramatic centre stone in any setting. Keep the look classic with a round brilliant diamond, or choose from our nine fancy-cut diamond options. As you shop our 3 carat selection, prioritize the diamond’s cut grade for the most brilliance.


24 of 2,068 3 Carat Diamonds

FAQs about 3 Carat diamonds

There is a wide variation of price for a 3 carat diamond, depending on the grade of the stone. Three-carat diamonds start around $20,000 and go up to around $124,000 or more.

The shape of the diamond varies the size of the 3 carat diamond. A round 3 carat diamond measures 9.3mm, while a 3 carat marquise-cut diamond measures 14 x 7mm. Our diamond carat size chart helps you compare all the shapes and carat weights.

Of all of the 4 Cs, the most important one to prioritize is cut. Cut refers to the proportions of the facets. An ideal cut maximizes the amount of light reflected through the diamond for brilliance, which is what makes our Astor by Blue Nile™ diamonds so popular.

Get the size of a 3 carat diamond at a lower price by shopping for a diamond with a weight of just under three carats.

Top 3 Carat Diamond Reviews

3 carat round diamond review

Best Experience Ever!

When it was time to pick out an engagement ring for my girlfriend, I was stressed... There are so many ring option and companies out there competing for your business. What drew me to Blue Nile was transparency. It’s so nice you can shop all the diamonds online and pick out the one that works best for you and your budget! I think I exchanged two or three emails and a couple phone calls with Amanda (who was awesome) at the Bellevue location. Signed up for the Blue Nile Visa card so I could make payments with no apr for the first year, at my own pace. Two weeks later it was ready for pickup in store! We are now happily engaged after proposing at the top of Whistler, Mallory has the ring of her dreams and I am no longer stressed
Tyler A. - Verified Buyer
Average Customer Rating $5 out of 5 stars
Classic Four Claw Solitaire Engagement Ring


A closeup of hands wearing an engagement ring and wedding band.

Excellent start to finish

Buying something new online is a bit daunting. Making a large purchase of something unique like a diamond is even more so. That makes the whole experience with Blue Nile so exceptional. And to calibrate when asked to give feedback it is rare that I am this positive on an experience. The visual tech is excellent. The data is excellent. When I called I had a live person on the phone in minutes. The product was excellent value and quality. The security of being able to return was essential in the buying process (although thankfully unnecessary here). Taking the chance to buy a 3 carat diamond online is a big jump and for us this just could not have been a better experience.
Todd B. - Verified Buyer
Average Customer Rating $5 out of 5 stars
Classic Comfort Fit Solitaire Engagement Ring
Platinum (2.5mm)


A closeup of someone holding a flower with an engagement and fashion ring on.

Radiant Cut Diamond Band

The quality of the diamond was significantly better in several categories:color, clarity and carat weight compared to other stones of the same price range at other vendors.
Leah M. - Verified Buyer
Average Customer Rating $5 out of 5 stars
Emerald Cut Diamond Engagement Ring
Platinum (0.96 ct. tw.)



Explore More Diamonds and Jewellery

Have questions about 3 Carat diamonds?

Get answers day or night.