Unit Converter

Quick conversions for PCB work: mm, mil, inch, µm and copper weight; temperature; dBm, watts and volts; frequency, period and free-space wavelength.

Related utilities tools

Impedance Calculator – Single-ended and differential microstrip, coated and embedded microstrip, stripline and coplanar lines, solved with a 2D field solver.
Propagation Delay, εeff & Timing – Propagation delay, length matching from skew, rise time to bandwidth, critical length and wavelength.
Crosstalk Calculator – Near- and far-end crosstalk between parallel traces from the field solver, with a sweep over the spacing (3W rule check).
Differential Via – Via-pair differential impedance through the plane clearance from a 2D field solution, antipad sizing for a target, stub resonance and delay.

Stackup Advisor – Enter board thickness, layer count and impedance requirements; the field solver ranks every matching fab stackup and gives the trace widths.
Layer Stack Manager – 178 fab stackups from 2 to 12 layers, editable, with any signal layer sent to the impedance calculator.

Junction Temperature – Junction temperature from power and the thermal-resistance chain (θJA or θJC + θCS + θSA), and the maximum power for a Tj limit.
Thermal Via Array – Thermal resistance of a via array under a hot pad, with plugged or filled vias, and the temperature drop through the board.

Trace Width, Current & Temperature Rise – IPC-2221: width for a current, current for a width, or temperature rise of a trace, with resistance, voltage drop and loss.
Via Calculator – Via current capacity, resistance, thermal resistance, capacitance, inductance and rise-time impact.
Skin Effect & AC Resistance – Skin depth in copper and the AC resistance of a trace across frequency.
Fusing Current – Current that melts a trace in a given time (Onderdonk), for fault and surge analysis.
Wire Gauge & Voltage Drop – AWG diameter, area and resistance, cable voltage drop and loss, the smallest gauge for a drop limit, and Preece fusing current.
Conductor Spacing (IPC-2221) – Minimum electrical clearance between conductors from IPC-2221 Table 6-1: internal, external, coated, high altitude, assemblies.

PDN Impedance Calculator – Target impedance, plane-pair capacitance, decoupling-capacitor resonance and the number of capacitors needed, with a log-log |Z|(f) plot.

Planar Spiral Inductor – Inductance of square, hexagonal, octagonal and circular PCB spirals (modified Wheeler and current-sheet models), with DC resistance and Q.
Through-Hole Padstack Calculator – Plated through-hole sizing per IPC-7251 / IPC-2221 / IPC-2222: hole, outer and inner pads, antipad, thermal relief and annular ring for levels A/B/C.
BGA Land Pattern – IPC-7351 land diameter for collapsing and non-collapsing BGA balls, with tolerance and courtyard, and escape-routing capacity between lands.

Ohm's Law & Power – Enter any two of voltage, current, resistance and power to get the other two.
Reactance & LC Resonance – XL and XC at a frequency, LC resonance, the L or C for a target frequency, and series/parallel LC impedance with Q.
Crystal Load Capacitors & PPM – Crystal load capacitors with the nearest E12/E24 values and resulting CL, plus frequency error ↔ ppm and clock drift.
Resistor Tools – Voltage divider with best E12/E24/E96 pairs, LED series resistor with power rating, and series/parallel R, C and L.
Attenuator Pads – Matched Pi, T and bridged-T pads with the nearest standard values, their actual loss and return loss, and resistor power.

Unit Converter – Length, copper weight, temperature, power (dBm/W/V) and frequency/wavelength.
Reference Charts – Drill sizes (number, letter, fractional, metric), ISO metric and Unified threads with tap and clearance drills, and the AWG wire table.