Pcb Trace Calculator Pro

PCB Trace Calculator helps you choose copper trace widths for your circuit boards and check whether existing traces are wide enough for the current they carry.

Instead of typing one current into a formula, you can sketch your circuit: place components, connect their pins with traces, and the app works out which traces carry which current. A battery feeding a fuse, a switch and two loads gives a wide main trunk and narrower branches, each sized for its own load. Signal and data lines stay at your normal signal width.

WHAT IT DOES
• Calculates trace width from current, copper thickness, allowed temperature rise and inner/outer layer (IPC-2221; optional IPC-2152 baseline estimate)
• Works out branch and trunk currents automatically when the circuit is clear, and tells you when it cannot
• Recognises power, ground, signal and data nets (I2C, SPI, UART, USB, CAN…)
• Warns when a trace is narrower than recommended, when a current is unknown, or when traces of different nets are too close
• Calculates electrical clearance from voltage (IPC-2221B table)
• Design check (DRC) with a list of problems; tap one to see it on the board

CHECK A KICAD BOARD
Open a .kicad_pcb file to check the real copper of your design. Track widths, pads and vias are imported; you enter the expected current of each power net and the app shows which traces or vias are too small. Copper pours are not imported.

EXPORT
• Text or PDF report of nets, currents and required widths
• KiCad net-class settings (table and JSON) you can copy into your project
• PNG image of the board and JSON project files

CALCULATORS
Trace width and clearance, via current, copper pour neck, voltage drop over a trace, Ohm's law and power, LED series resistor with standard E12/E24 values, voltage divider.

ALSO INCLUDED
• Component library with standard schematic symbols: resistors, capacitors, diodes, LEDs, transistors, MOSFETs, regulators, DC-DC converters, connectors, motors, relays and more
• Templates: H-bridge motor driver, LED strip driver, buck converter, battery + BMS, relay board
• Undo/redo, zoom and pan, mm or mil units, light and dark theme

PRIVACY
Works completely offline. No account, no internet permission. Your projects are saved only where you choose.

PLEASE NOTE
This is an engineering aid. All widths are calculated estimates and a starting point for your design, not guaranteed safe values. Real temperature rise also depends on copper planes, board thickness, nearby parts and airflow. High-voltage designs and high-speed signals (USB, HDMI, RF) need further review; impedance is not calculated. Always check your manufacturer's capabilities and the standards that apply to your product.