PCB Trace width shows how wide the copper line should be on your PCB. The width depends on how much current it carries and how thick the copper is. You can use this table to see common values and decide the right width for your design.
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Advanced PCB Trace Width & Impedance Calculator
Reference Table
| Parameter | Description | Typical Range or Value |
|---|---|---|
| Current (Amps) | Depends on the current and thickness | 0.1 A – 30 A or more |
| Temperature rise (°C) | Allowed increase over ambient temperature | 10°C – 30°C |
| Trace thickness (oz) | Copper thickness, usually 1 oz = 35 μm | 0.5 oz, 1 oz, 2 oz common |
| Trace width (mils/mm) | Depends on the current and thickness | Depends on current and thickness |
How to Use the Calculator
Open the calculator and choose layer type: external or internal. External layers cool better and need narrower widths for the same current.
Then pick a mode:
- Current → Width: Enter current (A), temperature rise (°C), and copper weight (oz). Click “Calculate” to see the width in millimeters.
- Width → Max Current: Enter width, temperature rise, and copper weight. Click “Calculate” to see the safe current.
For impedance, switch to Impedance mode. Enter trace width, board thickness, dielectric constant, and copper weight. Click “Calculate” to get the impedance (Ω).
Key Values
Use about 0.15 mm for 0.1 A, 1.2 mm for 1 A, and 10 mm for 10 A (1 oz copper, 10 °C rise). Adjust these if you choose 2 oz or 3 oz copper or allow a larger temperature rise.
Why It Matters
A too-thin trace overheats and may fail. A too-wide trace wastes space and adds cost. The correct width ensures safe operation and efficient use of board area.
FAQ
Use the internal layer mode. Internal layers need slightly wider traces for the same current.
