How big is a 5 carat Asscher cut diamond?

By HeyGema™ · Updated November 5, 2026

In short

A 5 carat Asscher cut diamond measures about 9.4 x 9.4 mm. It faces up 16% smaller than a round diamond of the same weight. On a size 6 finger it covers 57% of the width. For the same weight, a round diamond is 11.0 mm.

9.4 x 9.4 mm5 carat asscher
0.37 x 0.37 inthe same in inches
-16%face-up size vs a round
57%of a size 6 finger's width

Carat to mm calculator

ShapeGemCarat

About 9.4 x 9.4 mm

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

5 ct asscher

9.4 x 9.4 mm

5 ct round

11.0 mm

Side by side

5 ct asscher inside 5 ct round

A 5 carat asscher diamond beside a 5 carat round, to the same scale.

5 carat asscher diamond size

A well-cut 5 carat Asscher cut diamond measures about 9.4 x 9.4 mm (0.37 x 0.37 inches) at a length-to-width ratio of 1.00:1. It faces up 16% smaller than a round diamond of the same weight. It weighs 1.00 grams.

5 carat asscher on a finger

9.4 mm stone on a 16.5 mm finger: it covers 57% of the widthA 5 carat asscher diamond on a size 6 finger.

4: Finger width: 14.9 mm; Asscher covers: 63%

5: Finger width: 15.7 mm; Asscher covers: 60%

6: Finger width: 16.5 mm; Asscher covers: 57%

7: Finger width: 17.3 mm; Asscher covers: 54%

8: Finger width: 18.1 mm; Asscher covers: 52%

9: Finger width: 18.9 mm; Asscher covers: 50%

US ring size	Finger width	Asscher covers
4	14.9 mm	63%
5	15.7 mm	60%
6	16.5 mm	57%
7	17.3 mm	54%
8	18.1 mm	52%
9	18.9 mm	50%

Asscher sizes near 5 carat

3.5 carat: Length x width: 8.4 x 8.4 mm; Round of the same weight: 9.8 mm

4 carat: Length x width: 8.7 x 8.7 mm; Round of the same weight: 10.2 mm

5 (this page): Length x width: 9.4 x 9.4 mm; Round of the same weight: 11.0 mm

6 carat: Length x width: 10.0 x 10.0 mm; Round of the same weight: 11.7 mm

8 carat: Length x width: 11.0 x 11.0 mm; Round of the same weight: 12.9 mm

Carat	Length x width	Round of the same weight
3.5 carat	8.4 x 8.4 mm	9.8 mm
4 carat	8.7 x 8.7 mm	10.2 mm
5 (this page)	9.4 x 9.4 mm	11.0 mm
6 carat	10.0 x 10.0 mm	11.7 mm
8 carat	11.0 x 11.0 mm	12.9 mm

5 carat in other shapes

Every row is a well-cut diamond of 5 carat. The last column is the face-up size against the asscher.

Round: Length x width: 11.0 mm; Against asscher: +18%

Oval: Length x width: 13.7 x 9.4 mm; Against asscher: +25%

Cushion: Length x width: 9.6 x 9.6 mm; Against asscher: +2%

Princess: Length x width: 9.4 x 9.4 mm; Against asscher: +9%

Emerald cut: Length x width: 12.0 x 8.5 mm; Against asscher: +23%

Radiant: Length x width: 11.1 x 8.5 mm; Against asscher: +16%

Pear: Length x width: 14.5 x 9.4 mm; Against asscher: +15%

Marquise: Length x width: 17.8 x 8.9 mm; Against asscher: +37%

Heart: Length x width: 11.1 x 11.1 mm; Against asscher: -2%

Trillion: Length x width: 12.0 x 12.0 mm; Against asscher: +2%

Baguette: Length x width: 13.7 x 6.8 mm; Against asscher: +16%

Shape	Length x width	Against asscher
Round	11.0 mm	+18%
Oval	13.7 x 9.4 mm	+25%
Cushion	9.6 x 9.6 mm	+2%
Princess	9.4 x 9.4 mm	+9%
Emerald cut	12.0 x 8.5 mm	+23%
Radiant	11.1 x 8.5 mm	+16%
Pear	14.5 x 9.4 mm	+15%
Marquise	17.8 x 8.9 mm	+37%
Heart	11.1 x 11.1 mm	-2%
Trillion	12.0 x 12.0 mm	+2%
Baguette	13.7 x 6.8 mm	+16%

Questions

A 5 carat Asscher cut diamond is about 9.4 x 9.4 mm at the usual 1.00:1 ratio.

No. Face-up, a 5 carat asscher is 16% smaller than a 5 carat round (11.0 mm).

There is no rule. The stone is 63% of the width of a size 4 finger and 52% of a size 8. Compare it with a ring you have tried on in the finger chart above.

Yes. A lab grown diamond has the same density as a mined one, so it measures the same for the same weight.