Copper Thickness Converter — oz · µm · mil

Convert copper weight between ounces per square foot, microns, and mils. Heavy copper starts at 3 oz; PCBark builds up to 20 oz.

Copper weight (oz/ft²)

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oz	µm	mil	Class
1	35	1.37	Standard
2	70	2.74	Standard
3	105	4.13	Heavy copper
4	140	5.49	Heavy copper
6	210	8.23	Heavy copper
10	350	13.7	Extreme copper
20	700	27.4	Extreme copper