Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Dielectric constant

Required number input.

Plane-to-trace height (mm)

Required number input.

Trace width (mm)

Required number input.

Trace thickness (mm)

Required number input.

Approximate symmetric stripline impedance as (60 / sqrt(er)) x ln(4 x h / (0.67 x pi x (0.8 x w + t))). The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Stripline impedance (Ω)

The resulting stripline impedance returned as a number.

• Compact electronics formulas omit some combination of tolerances, temperature drift, bandwidth, loading, parasitics, noise spectrum, nonlinearity, clipping, calibration, layout, and device-specific limits. Typical datasheet values are not guaranteed limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• CPW Impedance Approx

  Approximate coplanar waveguide impedance as (60 / sqrt(er_eff)) x ln(4 x a / b) with a = w/2 + gap and b = w/2; er_eff defaults to 4.

• Microstrip Z Approx

  Approximate microstrip characteristic impedance as (87 / sqrt(er + 1.41)) x ln(5.98 x h / (0.8 x w + t)).

• Differential Z Approx

  Approximate edge-coupled differential impedance as 2 x z0 x (1 - 0.48 x exp(-0.96 x s / h)).