How big is a 4 carat cubic zirconia?
By HeyGema™ · Updated
In short
A 4 carat round cubic zirconia measures about 8.7 mm across (0.34 inches), 15% narrower than a 4 carat diamond (10.2 mm). An oval of the same weight is 10.8 x 7.4 mm and an emerald cut 9.4 x 6.7 mm.
- 8.7 mmround cubic zirconia, across
- 0.34 inthe same in inches
- 0.80 gweight
- 53%of a size 6 finger's width
Carat to mm calculator
About 8.7 x 8.7 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round
8.7 mm
Oval
10.8 x 7.4 mm
Cushion
7.5 x 7.5 mm
Princess
7.4 x 7.4 mm
Emerald cut
9.4 x 6.7 mm
Asscher
7.4 x 7.4 mm
Radiant
8.7 x 6.7 mm
Pear
11.4 x 7.4 mm
Marquise
14.0 x 7.0 mm
Heart
8.7 x 8.7 mm
Trillion
9.4 x 9.4 mm
Baguette
10.8 x 5.4 mm
= 5 mm in every picture above
4 carat cubic zirconia size by shape
Face-up measurements of a well-cut 4 carat cubic zirconia. Cubic zirconia is denser than diamond (5.80 against 3.52), so it packs more weight into less space and faces up 15% narrower for the same weight.
- Round
- Length x width: 8.7 mm
- In inches: 0.34 in
- Oval
- Length x width: 10.8 x 7.4 mm
- In inches: 0.42 x 0.29 in
- Cushion
- Length x width: 7.5 x 7.5 mm
- In inches: 0.30 x 0.30 in
- Princess
- Length x width: 7.4 x 7.4 mm
- In inches: 0.29 x 0.29 in
- Emerald cut
- Length x width: 9.4 x 6.7 mm
- In inches: 0.37 x 0.26 in
- Asscher
- Length x width: 7.4 x 7.4 mm
- In inches: 0.29 x 0.29 in
- Radiant
- Length x width: 8.7 x 6.7 mm
- In inches: 0.34 x 0.26 in
- Pear
- Length x width: 11.4 x 7.4 mm
- In inches: 0.45 x 0.29 in
- Marquise
- Length x width: 14.0 x 7.0 mm
- In inches: 0.55 x 0.28 in
- Heart
- Length x width: 8.7 x 8.7 mm
- In inches: 0.34 x 0.34 in
- Trillion
- Length x width: 9.4 x 9.4 mm
- In inches: 0.37 x 0.37 in
- Baguette
- Length x width: 10.8 x 5.4 mm
- In inches: 0.42 x 0.21 in
4 carat cubic zirconia against other gems
- Diamond
- Round, 4 carat: 10.2 mm
- Moissanite
- Round, 4 carat: 10.5 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
- Cubic zirconia (this page)
- Round, 4 carat: 8.7 mm
4 carat cubic zirconia on a finger
- 4
- Finger width: 14.9 mm
- Round covers: 58%
- Oval covers: 50%
- 5
- Finger width: 15.7 mm
- Round covers: 55%
- Oval covers: 47%
- 6
- Finger width: 16.5 mm
- Round covers: 53%
- Oval covers: 45%
- 7
- Finger width: 17.3 mm
- Round covers: 50%
- Oval covers: 43%
- 8
- Finger width: 18.1 mm
- Round covers: 48%
- Oval covers: 41%
- 9
- Finger width: 18.9 mm
- Round covers: 46%
- Oval covers: 39%
Cubic zirconia at nearby weights
- 3 carat cubic zirconia
- Round diameter: 7.9 mm
- 4 ct (this page)
- Round diameter: 8.7 mm
- 5 carat cubic zirconia
- Round diameter: 9.3 mm
Questions
A round 4 carat cubic zirconia is about 8.7 mm across. Other shapes are longer than they are wide: an oval is 10.8 x 7.4 mm.
No. A round 4 carat cubic zirconia is 15% narrower than a 4 carat diamond (10.2 mm).
0.80 grams. A carat is 200 milligrams for every gem.
A round 4 carat cubic zirconia covers 53% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.