convertimate Diamond carat to mm

Carats to points

Type a value in ct to get it in pt instantly.

50pt

That's about the same as a half-carat diamond. A well-cut round brilliant 5.122 mm across weighs about 0.5 ct.

What it means

How big is that stone?

For well-cut round brilliants. Deep stones weigh more for their spread and shallow ones less; other shapes and gems differ.

The math

How to convert ct to pt

For a round brilliant: carats ≈ 0.00372 × diameter³ (diameter in mm), so diameter ≈ ∛(carats ÷ 0.00372).

Example: 0.5 ct = 50 pt.

Every unit

That diamond in every unit

Tables

ct to pt conversion table

ct to pt conversion table
ctpt
0.1 ct10 pt
0.2 ct20 pt
0.25 ct25 pt
0.3 ct30 pt
0.4 ct40 pt
0.5 ct50 pt
0.75 ct75 pt
1 ct100 pt
1.25 ct125 pt
1.5 ct150 pt
2 ct200 pt
2.5 ct250 pt
3 ct300 pt
4 ct400 pt
5 ct500 pt
pt to ct conversion table
pt to ct conversion table
ptct
0.1 pt0.001 ct
0.2 pt0.002 ct
0.25 pt0.0025 ct
0.3 pt0.003 ct
0.4 pt0.004 ct
0.5 pt0.005 ct
0.75 pt0.0075 ct
1 pt0.01 ct
1.25 pt0.0125 ct
1.5 pt0.015 ct
2 pt0.02 ct
2.5 pt0.025 ct
3 pt0.03 ct
4 pt0.04 ct
5 pt0.05 ct

Quick answers

Quick answers

How many pt is 1 ct?
1 ct is 100 pt.
How many pt is 10 ct?
10 ct is 1,000 pt.
How many pt is 0.5 ct?
0.5 ct is 50 pt.

The units

About these units

Carats (ct)

The weight of the stone: 0.2 g per carat.

Points (pt)

Hundredths of a carat: a 50 pointer is half a carat.

Learn more about diamond units

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