Copper Thickness Converter
Convert between oz, µm, mil, and mm for PCB copper weight
Convert Copper Thickness
Conversion Results
Click any result to use it as input
Standard Copper Weights Reference
| Weight | oz/ft² | µm | mil | mm |
|---|---|---|---|---|
| 1/4 oz (Ultra-thin) | 0.25 | 8.8 | 0.34 | 0.009 |
| 1/2 oz (Standard signal) | 0.5 | 17.5 | 0.69 | 0.018 |
| 1 oz (Most common) | 1 | 35.0 | 1.37 | 0.035 |
| 2 oz (Power/high current) | 2 | 70.0 | 2.74 | 0.070 |
| 3 oz (Heavy copper) | 3 | 105.0 | 4.11 | 0.105 |
| 4 oz (Heavy copper) | 4 | 140.0 | 5.48 | 0.140 |
| 6 oz (Extreme power) | 6 | 210.0 | 8.22 | 0.210 |
Click any row to use as input
Copper Weight Basics
1 oz copper refers to the weight of copper spread over 1 square foot, which equals 35 µm thickness.
This is the most common copper weight for standard PCBs, suitable for most signal traces and moderate current applications.
When to Use Each Weight
- 0.5 oz: Fine-pitch components, HDI boards
- 1 oz: Standard signal traces, most applications
- 2 oz: Power traces, high current (>2A)
- 3+ oz: Heavy copper, power electronics
Understanding PCB Copper Thickness
Why Copper Weight Matters
Copper thickness directly affects current carrying capacity, heat dissipation, and impedance. Choosing the right copper weight is essential for reliable PCB performance.
- Thicker copper carries more current without overheating
- Better heat spreading for power components
- Lower trace resistance reduces voltage drop
- Affects trace width calculations for impedance control
Manufacturing Considerations
Heavier copper requires adjusted design rules for reliable manufacturing:
- 2 oz: Minimum trace/space typically 6/6 mil
- 3 oz: Minimum trace/space typically 8/8 mil
- 4 oz: Minimum trace/space typically 10/10 mil
- Thicker copper may require longer etching, affecting undercut