convertimate Diamond carat to mm

Points to carats

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

0.005ct

Nothing on our list is smaller: a pavé (melee) stone is 1.26× bigger. A well-cut round brilliant 1.104 mm across weighs about 0.005 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 pt to ct

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

Example: 0.5 pt = 0.005 ct.

Every unit

That diamond in every unit

Tables

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
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

Quick answers

Quick answers

How many ct is 1 pt?
1 pt is 0.01 ct.
How many ct is 10 pt?
10 pt is 0.1 ct.
How many ct is 0.5 pt?
0.5 pt is 0.005 ct.

The units

About these units

Points (pt)

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

Carats (ct)

The weight of the stone: 0.2 g per carat.

Learn more about diamond units

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