Diamond Size Chart

Round Diamonds MM x Carat

Approximate based on averages. Browse our pear diamond sizes and oval diamond sizes.

Diamond Size (MM) Carat Weight
4.0 mm
0.25 ct
5.1 mm
5.8 mm
6.4 mm
6.9 mm
7.3 mm
7.7 mm
1.75 ct
8.1 mm
8.5 mm
2.25 ct
8.9 mm
2.5 ct
9.0 mm
2.75 ct
9.3 mm
9.5 mm
3.25 ct
9.75 mm
3.5 ct
9.9 mm
3.75 ct
10.1 mm
0.40 carat diamond ring

0.40 carat diamond ring.

0.70 carat diamond ring.

0.90 carat diamond ring.

1.40 carat diamond ring.

1.75 carat diamond ring.

2.50 carat diamond ring.

Round Diamonds of Different Sizes on Hand

Diamonds of Different Sizes on Hand

comparing round diamonds 0.70, 0.94 and 1.23 carats
pear diamonds of different sizes, 1, 1.5, 2 carats

Factors That Affect a Diamond's Apparent Size

Several design elements can help accentuate a diamond's apparent size, from a diamond's cut and shape to the setting and style of a ring.

A halo setting, which is a surrounding of diamonds or other stones around the center stone, is one way to accentuate the appearance of a center stone. A three-stone setting, where the center stone is accompanied by side stones, also adds a little extra sparkle, as does a pavé setting.

An oval diamond or gemstone with a longer form, can elongate the appearance of a ring.  

But size is just one consideration. We always advise our clients to choose the style or shape that most appeals to them, and go from there.

Our three-stone Kate ring shown with a 1.0 and 1.5 carat oval diamond.

Our oval Rachael halo ring shown in a variety of diamonds.

Our pear-shaped Lauren shown in a plain band and a pave band.

Two 1.5 carat diamond rings - the top is a round diamond and the bottom is a cushion cut diamond.

Our Daya ring shown with a 3 carat, 2 carat and 1 carat diamond.

Quiz: Guess the Size of These Diamonds

Have questions? We're happy to help.