PCB Trace Width Calculator
Calculate optimal PCB trace width for current carrying capacity using IPC-2221 standards
Calculate PCB Trace Width
External traces have better heat dissipation than internal traces
Maximum continuous current through the trace
Standard copper thickness: 1 oz/ft² = 35 μm
Acceptable temperature rise above ambient (typically 10-20°C)
Unit for displaying trace width results
PCB Trace Width Results
Formula: W = A^1.378 / t, where A = (I / (k × T_rise^0.44))^(1/0.725)
Standard: IPC-2221 (k=0.048)
Safety factor: Consider adding 20-50% margin for production variations
Additional Parameters (Optional)
Width Analysis
Example Calculation
5V Power Supply Trace
Requirements: 3A continuous current
Copper thickness: 1 oz/ft² (standard)
Max temperature rise: 10°C
Location: External trace
Calculation Steps
A = (3 / (0.048 × 10^0.44))^(1/0.725) = 87.4 mil²
W = 87.4^1.378 / 1 = 0.87 × 87.4 = 76.0 mil
Result: 76 mil (1.93 mm) minimum width
Recommended: 100 mil (2.54 mm) with safety margin
Standard Copper Thicknesses
Temperature Rise Guidelines
Conservative: <10°C
High reliability applications
Standard: 10-20°C
Most commercial applications
Aggressive: 20-30°C
Cost-sensitive designs
Avoid: >30°C
May affect component reliability
Design Tips
Use copper pours for high-current traces
External traces handle current better than internal
Add 20-50% margin for manufacturing tolerance
Consider thermal vias for heat dissipation
Use multiple parallel traces for very high current
Keep high-current traces short and direct
Understanding PCB Trace Width
What is PCB Trace Width?
PCB trace width is the physical width of copper tracks on a printed circuit board. Proper trace width ensures the track can safely carry the required current without excessive heating or voltage drop.
Why is it Important?
- •Prevents overheating and component damage
- •Minimizes voltage drops in power distribution
- •Ensures reliable operation and longevity
- •Optimizes space usage and material costs
IPC-2221 Formula
A = (I / (k × T_rise^0.44))^(1/0.725)
W = A^1.378 / t
- A: Cross-sectional area (mil²)
- W: Trace width (mil)
- I: Maximum current (A)
- k: 0.048 (external), 0.024 (internal)
- T_rise: Temperature rise (°C)
- t: Trace thickness (oz/ft²)
Note: This calculator uses the IPC-2221 standard, which is widely accepted for PCB trace current capacity calculations.
Factors Affecting Trace Width
Current Capacity
Higher currents require wider traces to prevent overheating.
Temperature Rise
Lower allowed temperature rise requires wider traces.
Copper Thickness
Thicker copper allows for narrower traces at the same current.
Trace Location
External traces dissipate heat better than internal traces.
Best Practices
Safety Margins
Add 20-50% to calculated width for manufacturing variations and safety.
High Current Design
Use copper pours, multiple parallel traces, or thicker copper.
Thermal Management
Consider thermal vias and heat dissipation in your design.
Manufacturing
Check with your PCB manufacturer for minimum trace width capabilities.