PCB Trace Width Calculator (IPC-2221)

Q1: Why do external traces carry more current than internal traces?
External traces have better heat dissipation due to direct air contact, whereas internal traces are insulated by the PCB substrate.

Q2: How does copper weight (oz) affect my design?
Copper weight refers to the thickness of the copper foil. Increasing copper weight (e.g., from 1oz to 2oz) allows for narrower traces for the same current level.

Q3: What is a safe 'Temperature Rise' setting?
A rise of 10°C to 20°C is typically standard for reliable design. Use lower values if your device operates in high-ambient-temperature environments.

Q4: What if the calculated width is too narrow for my PCB manufacturer?
You should increase the copper weight, use thicker copper, or split the current between multiple parallel traces.

Q5: What is IPC-2221?
It is the industry-standard specification for Printed Board Design, defining the relationship between conductor size, current, and temperature.

Q6: Is this tool suitable for high-frequency or RF designs?
This calculator focuses on DC/low-frequency thermal limits. High-frequency designs require additional considerations like skin effect and impedance matching.

Q7: What does 'mils' stand for?
A 'mil' is a unit of length in the imperial system, where 1 mil = 0.001 inches (approx. 0.0254 mm).