PCB Trace Width Calculator
Professional PCB Design & Analysis Tools
Calculate PCB trace width from current, temperature rise, and copper weight using the IPC-2221 empirical power-law. Our free online trace width calculator helps hardware engineers estimate the minimum conductor width for a given current, temperature rise, and copper weight.
IPC-2221 Power-Law Model
Our PCB trace width calculator applies the IPC-2221 empirical formula (I = k × ΔT^0.44 × A^0.725). The result is an estimate: confirm critical designs against your fabricator's stackup and a thermal measurement or field solver.
Precise Calculations
Get accurate results for trace width, resistance, voltage drop, and power dissipation. Supports both internal and external layer calculations with automatic unit conversion between mils and millimeters.
Engineering-Grade Tools
Beyond basic trace width calculation, access our complete tool suite including via current calculator and impedance calculator for comprehensive PCB design.
Input Parameters
MOD: TR_WID_V1Results
Analysis & Recommendations
Design Guidance
- •1A on External layer, min width: 0.30mm
- •Add 10-20% safety margin. Recommended: 0.35mm
- •Cross-sectional area: 16.30 mil² (0.0105 mm²)
Electrical Impact
- •Resistance (10mm trace): 17.04 mΩ
- •Voltage drop: 17.04 mV
- •Power dissipation: 17.04 mW
IPC-2221 Calculation Method
This calculation uses the IPC-2221 standard formula: I = k × ΔT^b × A^c where k=0.048, b=0.44, c=0.725. External layers dissipate heat more effectively to surrounding air
Why Use Our PCB Trace Width Calculator?
Thermal Design Optimization
Our PCB trace width calculator applies the IPC-2221 empirical formula (I = k × ΔT^0.44 × A^0.725). The result is an estimate: confirm critical designs against your fabricator's stackup and a thermal measurement or field solver.
Internal vs External Layer Support
Under the IPC-2221 formula, an internal layer (k=0.024) carries about half the current of an external layer (k=0.048) at the same copper cross-section and temperature rise. Our trace calculator applies these constants; the result is an estimate.
Complete Electrical Analysis
Beyond trace width, calculate DC resistance, voltage drop, and power loss to ensure your power distribution network meets design requirements.
High Current Designs (1A - 35A+)
Our PCB trace width calculator applies the IPC-2221 empirical formula (I = k × ΔT^0.44 × A^0.725). The result is an estimate: confirm critical designs against your fabricator's stackup and a thermal measurement or field solver.
Copy & Export Results
Easily copy calculated trace widths and parameters for documentation, design reviews, or integration into your PCB CAD software.
100% Free, No Registration
Instant access to professional-grade PCB trace calculations. No signup, no subscription, unlimited use. Built by engineers, for engineers.
Complete PCB Design Calculator Suite
Our trace width calculator is part of a comprehensive toolkit for PCB designers. Use these companion tools for complete electrical and thermal analysis.
Via Current Calculator
LIVECalculate via current carrying capacity based on IPC-2221 standard. Free tool for plated through-hole thermal analysis and via array design optimization.
Try Calculator →Impedance Calculator
LIVEEstimate single-ended Z0 for isolated microstrip and stripline traces. Confirm the stackup and model limits with your fabricator.
Try Calculator →Frequently Asked Questions
PCB Trace Width Quick Reference
*Approximate values at 10°C rise. Use calculator for precise results.
Via Current Reference
→ Full Via CalculatorIPC-2221 Standard Formula
- I = Current (Amps)
- k = 0.048 (External) / 0.024 (Internal)
- ΔT = Temperature Rise (°C)
- A = Cross-sectional Area (mil²)
Why Choose TraceWidthCalculator
- VS Saturn PCBFaster UI
- VS 4PCB OnlineMore Precise
- VS Altium Tool100% Free
- VS EEWeb CalcBetter UX
Related Articles & Guides
PCB Relay Output Trace Width: Contact Current, Inrush, and Copper Sizing
Practical PCB relay-output trace-width guidance for contact current, inrush loads, fuse coordination, terminal exits, copper weight, vias, and supplier release checks.
PCB Power Plane Current Capacity: Copper Pours, Neck-Downs, and Vias
Practical PCB power-plane current guidance for copper pours, plane neck-downs, via arrays, voltage drop, thermal rise, and supplier release checks.
PCB Parallel Traces: Current Sharing, Vias, and Copper Width Rules
Practical rules for splitting PCB current across parallel traces, copper pours, and layers without creating hot vias, narrow neck-downs, or false copper margin.
USB-C VBUS Trace Width: 3A and 5A PD Copper Sizing Guide
Practical USB-C VBUS trace-width guidance for 3A and 5A USB Power Delivery boards, connector escapes, voltage drop, copper weight, vias, fuses, and buyer release checks.
Other PCB Calculators
Via Current Calculator
Calculate via current carrying capacity based on IPC-2221 standard. Free tool for plated through-hole thermal analysis and via array design optimization.
Try Calculator →Impedance Calculator
Estimate single-ended Z0 for isolated microstrip and stripline traces. Confirm the stackup and model limits with your fabricator.
Try Calculator →Related Tools & Resources
Via Current Calculator
CalculatorCalculate via current carrying capacity based on IPC-2221 standard. Free tool for plated through-hole thermal analysis and via array design optimization.
Impedance Calculator
CalculatorEstimate single-ended Z0 for isolated microstrip and stripline traces. Confirm the stackup and model limits with your fabricator.
Current Capacity Calculator
CalculatorDetermine maximum current a trace can safely carry
Differential impedance reference (numeric results unavailable)
CalculatorReference for differential pair impedance targets and routing rules. Numeric differential calculation is temporarily unavailable while the model is validated; single-ended Z0 is available.
Pad Size Calculator
CalculatorCalculate pad diameter and area from hole size and annular ring
Thermal Relief Calculator
CalculatorDesign thermal relief patterns for solderable plane connections
Ready to Calculate Your PCB Trace Width?
Use the free IPC-2221 trace width calculator above, or explore our other PCB design tools for comprehensive electrical analysis. Check out our blog for in-depth PCB design guides and tutorials.