How big is a 0.5 carat moissanite?

By HeyGema™ · Updated

In short

A 0.5 carat round moissanite measures about 5.3 mm across (0.21 inches), 3% wider than a 0.5 carat diamond (5.1 mm). An oval of the same weight is 6.5 x 4.5 mm and an emerald cut 5.7 x 4.1 mm.

Carat to mm calculator

About 5.3 x 5.3 mm

An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.

Round
5.3 mm
Oval
6.5 x 4.5 mm
Cushion
4.6 x 4.6 mm
Princess
4.5 x 4.5 mm
Emerald cut
5.7 x 4.1 mm
Asscher
4.5 x 4.5 mm
Radiant
5.3 x 4.1 mm
Pear
6.9 x 4.5 mm
Marquise
8.5 x 4.3 mm
Heart
5.3 x 5.3 mm
Trillion
5.7 x 5.7 mm
Baguette
6.5 x 3.3 mm
= 2 mm in every picture above
A 0.5 carat moissanite in 12 shapes, drawn to one scale.

0.5 carat moissanite size by shape

Face-up measurements of a well-cut 0.5 carat moissanite. Moissanite is lighter than diamond (3.22 against 3.52), so the same weight gives a bigger stone, 3% wider across.

Round
Length x width: 5.3 mm
In inches: 0.21 in
Oval
Length x width: 6.5 x 4.5 mm
In inches: 0.26 x 0.18 in
Cushion
Length x width: 4.6 x 4.6 mm
In inches: 0.18 x 0.18 in
Princess
Length x width: 4.5 x 4.5 mm
In inches: 0.18 x 0.18 in
Emerald cut
Length x width: 5.7 x 4.1 mm
In inches: 0.23 x 0.16 in
Asscher
Length x width: 4.5 x 4.5 mm
In inches: 0.18 x 0.18 in
Radiant
Length x width: 5.3 x 4.1 mm
In inches: 0.21 x 0.16 in
Pear
Length x width: 6.9 x 4.5 mm
In inches: 0.27 x 0.18 in
Marquise
Length x width: 8.5 x 4.3 mm
In inches: 0.33 x 0.17 in
Heart
Length x width: 5.3 x 5.3 mm
In inches: 0.21 x 0.21 in
Trillion
Length x width: 5.7 x 5.7 mm
In inches: 0.23 x 0.23 in
Baguette
Length x width: 6.5 x 3.3 mm
In inches: 0.26 x 0.13 in

0.5 carat moissanite against other gems

Diamond
Round, 0.5 carat: 5.1 mm
Sapphire
Round, 0.5 carat: 4.9 mm
Ruby
Round, 0.5 carat: 4.9 mm
Emerald
Round, 0.5 carat: 5.6 mm
Aquamarine
Round, 0.5 carat: 5.6 mm
Morganite
Round, 0.5 carat: 5.5 mm
Tanzanite
Round, 0.5 carat: 5.2 mm
Topaz
Round, 0.5 carat: 5.1 mm
Moissanite (this page)
Round, 0.5 carat: 5.3 mm

0.5 carat moissanite on a finger

5.3 mm
5.3 mm stone on a 16.5 mm finger: it covers 32% of the widthA round 0.5 carat moissanite on a size 6 finger.
4
Finger width: 14.9 mm
Round covers: 35%
Oval covers: 30%
5
Finger width: 15.7 mm
Round covers: 34%
Oval covers: 29%
6
Finger width: 16.5 mm
Round covers: 32%
Oval covers: 27%
7
Finger width: 17.3 mm
Round covers: 30%
Oval covers: 26%
8
Finger width: 18.1 mm
Round covers: 29%
Oval covers: 25%
9
Finger width: 18.9 mm
Round covers: 28%
Oval covers: 24%

Moissanite at nearby weights

0.5 ct (this page)
Round diameter: 5.3 mm
1 carat moissanite
Round diameter: 6.6 mm

Questions

A round 0.5 carat moissanite is about 5.3 mm across. Other shapes are longer than they are wide: an oval is 6.5 x 4.5 mm.
Yes. A round 0.5 carat moissanite is 3% wider than a 0.5 carat diamond (5.1 mm).
0.10 grams. A carat is 200 milligrams for every gem.
A round 0.5 carat moissanite covers 32% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.

More size charts