Convert oz to copper thickness
The copper foil thickness of a printed circuit board is often specified by weight in ounces (oz). 1 oz is about 0.035 mm.
oz
Copper thickness
0.035mm
History
Press Enter in any field to keep a snapshot here.
Formula
Copper thickness: t[mm] = oz × 0.035
1 oz ≈ 35 µm = 0.035 mm
1 oz ≈ 35 µm = 0.035 mm
Design notes
In PCB specifications, "1 oz copper" means one ounce of copper spread over one square foot, which corresponds to a thickness of 35 µm (0.035 mm).
Common copper weights:
• 0.5 oz (18 µm): inner layers and fine-pitch routing
• 1 oz (35 µm): standard outer layers and general signals
• 2 oz (70 µm): high-current traces
• 3 oz and above: power boards and supply circuits
Thicker copper forces a wider minimum trace width because of etching tolerance. Check the capability table of your board manufacturer.