Fascinating Diamonds

Diamond Size Chart

Radiant Diamond Size Chart

Radiant cut diamonds have trimmed corners and a brilliant cut style that blends round sparkle with an emerald-like outline.

Average Radiant Diamond Sizes

  • 0.50 carat ≈ 5 x 4 mm
  • 1.00 carat ≈ 6.5 x 5.5 mm
  • 2.00 carat ≈ 8 x 7 mm

Tip: Rectangular radiants often look bigger than square ones of the same carat.

Select a diamond shape.

  • Round
  • Princess
  • Asscher
  • Heart
  • Marquise
  • Oval
  • Radiant
  • Emerald
  • Pear
  • Cushion

MM Size Carat Weight
4.3x3 mm.0.25 ct.
4.5x3.5 mm.0.34 ct.
6x3 mm.0.41 ct.
6x4 mm.0.50 ct.
6.5x4.5 mm.0.75 ct.
7x5 mm.1.00 ct.
7.3x5.5 mm.1.25 ct.
7.5x5.8 mm.1.50 ct.
8x6 mm.1.75 ct.
Radiant Diamond Illustration
MM Size Carat Weight
8.2x6.2 mm.2.00 ct.
8.5x6.5 mm.2.25 ct.
9x7 mm.2.50 ct.
9.5x7.5 mm.3.00 ct.
10x7 mm.3.31 ct.
10x8 mm.3.50 ct.
10.2x8.2 mm.4.00 ct.
10.5x8.5 mm.4.50 ct.
11x9 mm.5.00 ct.
MM Size Carat Weight
11.5x10 mm.6.45 ct.
12x9 mm.6.06 ct.
13x9 mm.6.54 ct.
13.2x9.2 mm.6.79 ct.
14x10 mm.8.47 ct.
13x11 mm.9.33 ct.
13.5x11.5 mm.10.19 ct.
15x11 mm.11.48 ct.
14x12 mm.12.14 ct.
16x12 mm.14.22 ct.
4cs of diamond guide

4cs of diamond guide

Begin your journey with our comprehensive online diamond education, and when you`re ready, our team of experts is here to answer your more detailed questions.

Loose Diamonds

Loose Diamonds

Create an engagement ring that celebrates your love and lifelong commitment. At Brilliance, every ring is meticulously handcrafted by our skilled artisans just for you.


Why Customers Love Fascinating Diamonds

  • Tim C

    Tim Calandrello

    ★★★★★

    I was extremely happy with my entire experience and the jewelry is gorgeous. There was also really great communication with the company when I had questions. They were professional, responsive and a pleasure to deal with. The item arrived exactly when they said it would and I couldn't be happier. I'll absolutely order from them again.

  • Bri

    Bri

    ★★★★★
    Beautiful, Excellent Communication

    Excellent, quick, effective communication. The ring I picked out came out even more beautiful than I expected.

  • Kevin M.

    Kevin M.

    ★★★★★
    As always, Raj has given perfect

    As always,Raj has given perfect product and service. I'm a customer for life

  • Caroline W

    Caroline Wooldridge

    ★★★★★

    Raj was very communicative, empathetic and proactive in trying to help me with my mother's birthday gift. Would recommend! FYI, Im not a big jewelry buyer so was unfamiliar with these kind of stores/offices, but it's like a small office on high floor. He has a variety of samples/examples there, but most are ordered / custom (vs a full retail store.)

  • Linda C

    Linda Courtney

    ★★★★★
    The ring I received is lovely

    The ring I received is lovely! There was an error to my order and they adjusted the difference promptly to my account. I would highly recommend this company!

  • Cynthia T.

    Cynthia T.

    ★★★★★
    Will definitely buy from again.

    Will definitely buy from again. Beautiful product, great communication, secure shipping.

  • Kevin Mcknight

    Kevin Mcknight

    ★★★★★

    I received the very best customer service ever!!!! Raj was absolutely awesome. The diamond ring we purchased is beautiful and very well made. I will be a return client for many years and occasions. Just the best retail experience online!!!!

  • FB

    FB

    ★★★★★
    Great Purchase

    Beautiful earrings and setting. Kind people that are always willing to answer questions.

  • Mirander

    Mirander

    ★★★★★
    good

    remarkable pendant with exquisite design. I am in love....thank you

Frequently Asked Questions

How do I use the Cushion Cut Diamond size chart?

The chart helps you see how each carat weight translates into millimeter dimensions, so you can visualize the actual size of your cushion diamond before buying.

Do cushion diamonds hide inclusions well?

Yes, the facet pattern of a cushion cut helps mask small inclusions better than step-cut shapes like emeralds or Asschers.

How can I make my cushion diamond appear larger?

Choose a halo setting or a slightly elongated ratio (around 1.15) to give the illusion of a bigger stone on your finger.

What makes cushion cut diamonds so popular for vintage-style rings?

Their rounded corners and soft edges resemble old mine cuts, giving cushion diamonds a timeless, romantic appeal that fits both modern and vintage designs.

What’s the best color grade for cushion cut diamonds?

Since cushion cuts tend to retain more color, grades between G and I are ideal for balancing warmth and sparkle—especially in yellow or rose gold settings.

What is the ideal ratio for a cushion cut diamond?

A length-to-width ratio between 1.00 and 1.10 gives a square shape, while 1.15 to 1.30 creates a more rectangular look.

Are all cushion diamonds the same shape?

No, cushion diamonds vary from square to rectangular, and the exact shape depends on the length-to-width ratio and cutting style.

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Terms & Conditions

Fascinating Diamonds supplies products listed on the Fascinating Diamonds, and Fascinating Diamonds websites, and in our stores under the following Terms and Conditions. Please read these Terms and Conditions, and our Privacy and Cookie Policies carefully before using any of our websites, or ordering from us.

The Terms and Conditions apply to your use of any Fascinating Diamonds website and to any products you purchase from them; regardless of how you access the website, including any technologies or devices where our website is available to you at home, on the move or in store

We reserve the right to update these Terms and Conditions at any time, and any updates affecting you or your purchases will be notified to you, by us in writing (via email), and on this page.

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