How big is a 4 carat moissanite?
By HeyGema™ · Updated
In short
A 4 carat round moissanite measures about 10.5 mm across (0.42 inches), 3% wider than a 4 carat diamond (10.2 mm). An oval of the same weight is 13.1 x 9.0 mm and an emerald cut 11.4 x 8.2 mm.
- 10.5 mmround moissanite, across
- 0.42 inthe same in inches
- 0.80 gweight
- 64%of a size 6 finger's width
Carat to mm calculator
About 10.5 x 10.5 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round
10.5 mm
Oval
13.1 x 9.0 mm
Cushion
9.2 x 9.2 mm
Princess
9.0 x 9.0 mm
Emerald cut
11.4 x 8.2 mm
Asscher
9.0 x 9.0 mm
Radiant
10.6 x 8.2 mm
Pear
13.9 x 9.0 mm
Marquise
17.0 x 8.5 mm
Heart
10.6 x 10.6 mm
Trillion
11.4 x 11.4 mm
Baguette
13.1 x 6.5 mm
= 5 mm in every picture above
4 carat moissanite size by shape
Face-up measurements of a well-cut 4 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: 10.5 mm
- In inches: 0.42 in
- Oval
- Length x width: 13.1 x 9.0 mm
- In inches: 0.52 x 0.35 in
- Cushion
- Length x width: 9.2 x 9.2 mm
- In inches: 0.36 x 0.36 in
- Princess
- Length x width: 9.0 x 9.0 mm
- In inches: 0.35 x 0.35 in
- Emerald cut
- Length x width: 11.4 x 8.2 mm
- In inches: 0.45 x 0.32 in
- Asscher
- Length x width: 9.0 x 9.0 mm
- In inches: 0.35 x 0.35 in
- Radiant
- Length x width: 10.6 x 8.2 mm
- In inches: 0.42 x 0.32 in
- Pear
- Length x width: 13.9 x 9.0 mm
- In inches: 0.55 x 0.35 in
- Marquise
- Length x width: 17.0 x 8.5 mm
- In inches: 0.67 x 0.33 in
- Heart
- Length x width: 10.6 x 10.6 mm
- In inches: 0.42 x 0.42 in
- Trillion
- Length x width: 11.4 x 11.4 mm
- In inches: 0.45 x 0.45 in
- Baguette
- Length x width: 13.1 x 6.5 mm
- In inches: 0.52 x 0.26 in
4 carat moissanite against other gems
- Diamond
- Round, 4 carat: 10.2 mm
- Sapphire
- Round, 4 carat: 9.8 mm
- Ruby
- Round, 4 carat: 9.8 mm
- Emerald
- Round, 4 carat: 11.2 mm
- Aquamarine
- Round, 4 carat: 11.2 mm
- Morganite
- Round, 4 carat: 11.1 mm
- Tanzanite
- Round, 4 carat: 10.4 mm
- Topaz
- Round, 4 carat: 10.2 mm
- Moissanite (this page)
- Round, 4 carat: 10.5 mm
4 carat moissanite on a finger
- 4
- Finger width: 14.9 mm
- Round covers: 71%
- Oval covers: 60%
- 5
- Finger width: 15.7 mm
- Round covers: 67%
- Oval covers: 57%
- 6
- Finger width: 16.5 mm
- Round covers: 64%
- Oval covers: 54%
- 7
- Finger width: 17.3 mm
- Round covers: 61%
- Oval covers: 52%
- 8
- Finger width: 18.1 mm
- Round covers: 58%
- Oval covers: 50%
- 9
- Finger width: 18.9 mm
- Round covers: 56%
- Oval covers: 47%
Moissanite at nearby weights
- 3 carat moissanite
- Round diameter: 9.6 mm
- 4 ct (this page)
- Round diameter: 10.5 mm
- 5 carat moissanite
- Round diameter: 11.4 mm
Questions
A round 4 carat moissanite is about 10.5 mm across. Other shapes are longer than they are wide: an oval is 13.1 x 9.0 mm.
Yes. A round 4 carat moissanite is 3% wider than a 4 carat diamond (10.2 mm).
0.80 grams. A carat is 200 milligrams for every gem.
A round 4 carat moissanite covers 64% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.