1. What is a PCB Wire Current Calculator?

Definition: This calculator estimates the current carrying capacity of PCB traces or wires based on temperature rise, cross-sectional area, and material properties.

Purpose: It helps electrical engineers and PCB designers determine safe current limits for traces to prevent overheating and ensure reliability.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current capacity (amps)
• \( \Delta T \) — Temperature rise above ambient (°C)
• \( A \) — Cross-sectional area (m²)
• \( k \) — Material constant (0.048 for copper)

Explanation: The formula accounts for how current capacity increases with larger trace areas but decreases with higher temperature rises.

3. Importance of PCB Current Calculation

Details: Proper current calculation prevents trace overheating, ensures signal integrity, and maintains PCB reliability over time.

4. Using the Calculator

Tips: Enter the desired temperature rise, trace cross-sectional area, and material constant (default 0.048 for copper). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical temperature rise (ΔT) value?
A: Common values range 10-20°C for general applications, up to 30-40°C for high-current designs.

Q2: How do I find cross-sectional area?
A: For rectangular traces: Area = width × thickness (convert all units to meters).

Q3: What k value should I use for different materials?
A: Use 0.048 for copper, 0.024 for aluminum, and 0.016 for brass.

Q4: Does this account for trace length?
A: No, this formula assumes adequate heat dissipation. For very long traces, consider additional derating.

Q5: Is this applicable for both internal and external layers?
A: This applies primarily to external layers. Internal traces typically have about 50% higher capacity due to better heat dissipation.