Round vs Pear diamond size

By HeyGema™ · Updated November 5, 2026

In short

A 1 carat round measures 6.5 mm and a 1 carat pear 8.5 x 5.5 mm. At the same weight a round faces up about 3% larger than a pear. In face-up terms, 1 carat of round looks like a 1.00 carat round and 1 carat of pear like a 0.96 carat round.

6.5 mm1 ct round
8.5 x 5.5 mm1 ct pear
-3%pear face-up vs round

Carat to mm calculator

ShapeGemCaratLength to width

About 8.5 x 5.5 mm

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

1 ct round

6.5 mm

1 ct pear

8.5 x 5.5 mm

Side by side

1 ct round inside 1 ct pear

A 1 carat round and a 1 carat pear diamond, to the same scale.

Round vs Pear diamond size at the same weight

At the same weight a round faces up about 3% larger than a pear. A 1 carat round measures 6.5 mm and a 1 carat pear 8.5 x 5.5 mm. A 1 carat round faces up like a 1.00 carat round, and a 1 carat pear like a 0.96 carat round.

0.5 carat: Round length x width: 5.1 mm; Pear length x width: 6.7 x 4.4 mm; Pear face-up vs round: -3%

0.75 carat: Round length x width: 5.9 mm; Pear length x width: 7.7 x 5.0 mm; Pear face-up vs round: -3%

1 carat: Round length x width: 6.5 mm; Pear length x width: 8.5 x 5.5 mm; Pear face-up vs round: -3%

1.5 carat: Round length x width: 7.4 mm; Pear length x width: 9.7 x 6.3 mm; Pear face-up vs round: -3%

2 carat: Round length x width: 8.1 mm; Pear length x width: 10.7 x 6.9 mm; Pear face-up vs round: -3%

3 carat: Round length x width: 9.3 mm; Pear length x width: 12.3 x 7.9 mm; Pear face-up vs round: -3%

Carat	Round length x width	Pear length x width	Pear face-up vs round
0.5 carat	5.1 mm	6.7 x 4.4 mm	-3%
0.75 carat	5.9 mm	7.7 x 5.0 mm	-3%
1 carat	6.5 mm	8.5 x 5.5 mm	-3%
1.5 carat	7.4 mm	9.7 x 6.3 mm	-3%
2 carat	8.1 mm	10.7 x 6.9 mm	-3%
3 carat	9.3 mm	12.3 x 7.9 mm	-3%

Round vs Pear on a finger

A 1 carat round covers 39% of the width of a size 6 finger and a 1 carat pear covers 33%. Long cuts sit along the finger, so their width is what shows across it.

6.3 mm stone on a 16.5 mm finger: it covers 38% of the widthA 1.5 carat pear on a size 6 finger.

4: Finger width: 14.9 mm; 1.5 ct round covers: 50%; 1.5 ct pear covers: 42%

5: Finger width: 15.7 mm; 1.5 ct round covers: 47%; 1.5 ct pear covers: 40%

6: Finger width: 16.5 mm; 1.5 ct round covers: 45%; 1.5 ct pear covers: 38%

7: Finger width: 17.3 mm; 1.5 ct round covers: 43%; 1.5 ct pear covers: 36%

8: Finger width: 18.1 mm; 1.5 ct round covers: 41%; 1.5 ct pear covers: 35%

US ring size	Finger width	1.5 ct round covers	1.5 ct pear covers
4	14.9 mm	50%	42%
5	15.7 mm	47%	40%
6	16.5 mm	45%	38%
7	17.3 mm	43%	36%
8	18.1 mm	41%	35%

Match the look, not only the carat

Because a pear needs about 1.04 carat to face up like 1 carat of round, comparing by weight alone hides the difference. Compare millimeters, or put both stones side by side in the size comparison tool.

Round and Pear size charts

Full charts from 0.25 to 5 carat: Round diamond size chart and Pear diamond size chart.

Questions

At the same weight a round faces up about 3% larger than a pear. Face-up area is what you see from above; the round has more of it at equal weight.

A 1 carat round is about 6.5 mm and a 1 carat pear about 8.5 x 5.5 mm, for a well-cut stone at the usual ratio.

A 2 carat round is 8.1 mm and a 2 carat pear is 10.7 x 6.9 mm. Face-up, the pear is -3% against the round.

A 1 carat round covers 39% of the width of a size 6 finger and a 1 carat pear 33%. The numbers change with ring size and with the stone's length-to-width ratio.