Points to carat converter: 100 points is 1 carat

By HeyGema™ · Updated November 5, 2026

In short

1 point = 0.01 carats. 1 carat = 100 points. The carat is exactly 200 milligrams (0.2 grams).

AmountFromTo

25 points = 0.25 carats

1 carat is exactly 200 milligrams (0.2 grams). A point is one hundredth of a carat.

Points to carats

A point is one hundredth of a carat. Jewelers call small stones by points: a 25 pointer is a quarter carat, a 50 pointer is half a carat. The last column gives the diameter of a round diamond of that weight.

1 point: Carats: 0.01 carats; Round diamond size: 1.39 mm

5 points: Carats: 0.05 carats; Round diamond size: 2.38 mm

10 points: Carats: 0.1 carats; Round diamond size: 2.99 mm

15 points: Carats: 0.15 carats; Round diamond size: 3.4 mm

20 points: Carats: 0.2 carats; Round diamond size: 3.8 mm

25 points: Carats: 0.25 carats; Round diamond size: 4.1 mm

30 points: Carats: 0.3 carats; Round diamond size: 4.3 mm

33 points: Carats: 0.33 carats; Round diamond size: 4.5 mm

40 points: Carats: 0.4 carats; Round diamond size: 4.8 mm

50 points: Carats: 0.5 carats; Round diamond size: 5.1 mm

60 points: Carats: 0.6 carats; Round diamond size: 5.4 mm

75 points: Carats: 0.75 carats; Round diamond size: 5.9 mm

90 points: Carats: 0.9 carats; Round diamond size: 6.2 mm

100 points: Carats: 1 carat; Round diamond size: 6.5 mm

150 points: Carats: 1.5 carats; Round diamond size: 7.4 mm

200 points: Carats: 2 carats; Round diamond size: 8.1 mm

Points	Carats	Round diamond size
1 point	0.01 carats	1.39 mm
5 points	0.05 carats	2.38 mm
10 points	0.1 carats	2.99 mm
15 points	0.15 carats	3.4 mm
20 points	0.2 carats	3.8 mm
25 points	0.25 carats	4.1 mm
30 points	0.3 carats	4.3 mm
33 points	0.33 carats	4.5 mm
40 points	0.4 carats	4.8 mm
50 points	0.5 carats	5.1 mm
60 points	0.6 carats	5.4 mm
75 points	0.75 carats	5.9 mm
90 points	0.9 carats	6.2 mm
100 points	1 carat	6.5 mm
150 points	1.5 carats	7.4 mm
200 points	2 carats	8.1 mm

Weight and size of common diamonds

For a sense of scale, this is what common round diamond weights come to in grams and milligrams, and how wide each stone is.

0.25 ct: In grams: 0.050 g; In milligrams: 50 mg; Round diamond size: 4.1 mm

0.5 ct: In grams: 0.10 g; In milligrams: 100 mg; Round diamond size: 5.1 mm

1 ct: In grams: 0.20 g; In milligrams: 200 mg; Round diamond size: 6.5 mm

2 ct: In grams: 0.40 g; In milligrams: 400 mg; Round diamond size: 8.1 mm

3 ct: In grams: 0.60 g; In milligrams: 600 mg; Round diamond size: 9.3 mm

5 ct: In grams: 1.00 g; In milligrams: 1000 mg; Round diamond size: 11.0 mm

10 ct: In grams: 2.00 g; In milligrams: 2000 mg; Round diamond size: 13.9 mm

Weight	In grams	In milligrams	Round diamond size
0.25 ct	0.050 g	50 mg	4.1 mm
0.5 ct	0.10 g	100 mg	5.1 mm
1 ct	0.20 g	200 mg	6.5 mm
2 ct	0.40 g	400 mg	8.1 mm
3 ct	0.60 g	600 mg	9.3 mm
5 ct	1.00 g	1000 mg	11.0 mm
10 ct	2.00 g	2000 mg	13.9 mm

Carats to points

1 carat = 100 points. For all weight units at once use the carat converter. For size instead of weight, see the carat to mm calculator.

Questions

1 carat is 100 points.

30 points is 0.30 carat, a round diamond about 4.3 mm across.

75 points is 0.75 carat.