Melee diamond size chart: mm to carat and stones per carat

By HeyGema™ · Updated November 5, 2026

In short

Melee diamonds are small stones used for pavé, halos and accents, and jewelers order them by size in mm. A 1.5 mm round weighs about 0.013 carat, so it takes about 80 stones to make a carat.

Carat to mm calculator

ShapeGemLength (mm)

About 0.01 carat

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

Round melee: mm to carat

Weight of one well-cut round stone at each size, and how many of that size weigh one carat in total. Real parcels vary with the cut, so treat the stone counts as a guide when you cost a piece.

0.8 mm: Weight of one stone: 0.0019 ct; Stones per carat: 524

0.9 mm: Weight of one stone: 0.0027 ct; Stones per carat: 368

1.0 mm: Weight of one stone: 0.0037 ct; Stones per carat: 268

1.10 mm: Weight of one stone: 0.0050 ct; Stones per carat: 202

1.2 mm: Weight of one stone: 0.0064 ct; Stones per carat: 155

1.3 mm: Weight of one stone: 0.0082 ct; Stones per carat: 122

1.4 mm: Weight of one stone: 0.0102 ct; Stones per carat: 98

1.5 mm: Weight of one stone: 0.0126 ct; Stones per carat: 80

1.6 mm: Weight of one stone: 0.0153 ct; Stones per carat: 66

1.7 mm: Weight of one stone: 0.0183 ct; Stones per carat: 55

1.8 mm: Weight of one stone: 0.0217 ct; Stones per carat: 46

1.9 mm: Weight of one stone: 0.0256 ct; Stones per carat: 39

2.0 mm: Weight of one stone: 0.0298 ct; Stones per carat: 34

2.1 mm: Weight of one stone: 0.0345 ct; Stones per carat: 29

2.20 mm: Weight of one stone: 0.0397 ct; Stones per carat: 25

2.30 mm: Weight of one stone: 0.0453 ct; Stones per carat: 22

2.4 mm: Weight of one stone: 0.0515 ct; Stones per carat: 19

2.5 mm: Weight of one stone: 0.0582 ct; Stones per carat: 17

2.6 mm: Weight of one stone: 0.0655 ct; Stones per carat: 15

2.7 mm: Weight of one stone: 0.0734 ct; Stones per carat: 14

2.8 mm: Weight of one stone: 0.0818 ct; Stones per carat: 12

2.9 mm: Weight of one stone: 0.0909 ct; Stones per carat: 11

3.0 mm: Weight of one stone: 0.1006 ct; Stones per carat: 10

3.25 mm: Weight of one stone: 0.1279 ct; Stones per carat: 8

3.5 mm: Weight of one stone: 0.1598 ct; Stones per carat: 6

Diameter	Weight of one stone	Stones per carat
0.8 mm	0.0019 ct	524
0.9 mm	0.0027 ct	368
1.0 mm	0.0037 ct	268
1.10 mm	0.0050 ct	202
1.2 mm	0.0064 ct	155
1.3 mm	0.0082 ct	122
1.4 mm	0.0102 ct	98
1.5 mm	0.0126 ct	80
1.6 mm	0.0153 ct	66
1.7 mm	0.0183 ct	55
1.8 mm	0.0217 ct	46
1.9 mm	0.0256 ct	39
2.0 mm	0.0298 ct	34
2.1 mm	0.0345 ct	29
2.20 mm	0.0397 ct	25
2.30 mm	0.0453 ct	22
2.4 mm	0.0515 ct	19
2.5 mm	0.0582 ct	17
2.6 mm	0.0655 ct	15
2.7 mm	0.0734 ct	14
2.8 mm	0.0818 ct	12
2.9 mm	0.0909 ct	11
3.0 mm	0.1006 ct	10
3.25 mm	0.1279 ct	8
3.5 mm	0.1598 ct	6

Below about 1.5 mm, melee is often cut thicker and with less standard proportions, and trade charts usually list somewhat heavier pieces than this chart. Use these figures to plan a design and your supplier's chart to place an order.

Using the chart for a design

For a pavé band, add up the weight of every stone: the number of stones times the weight of one. For a halo, count the stones around the center stone and multiply. Round the total up a little, because stones lost in setting and cutting are not free.

Questions

There is no single cutoff. Melee usually means a small stone, often under about 0.2 carat or under 3 mm across, set in groups.

About 34 round stones of 2 mm make a carat.

This chart is for a well-cut round of standard proportions. Very small stones are often cut thicker, so a supplier's chart usually lists a somewhat higher weight below about 1.5 mm. Use the supplier's figures for an order.

A 1.3 mm round diamond weighs about 0.0082 carat.