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.

AL value (nH/turn^2)

Optional number input.

Turns

Required integer input.

Compute toroid inductance in microhenries as AL (nH per turn squared) times the square of the turns divided by 1000. 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]

Inductance (uH)

The resulting inductance 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.

• Powder Core AL Inductance

  Calculate inductance L=AL·N² from a core's inductance factor and turn count. AL and output use the same unit per turn squared; account for DC bias separately because effective permeability can fall.

• Coax L Per Meter

  Compute coaxial cable inductance per meter as 200 x ln(d_outer/d_inner) nH/m from the loop inductance mu_0/2pi x ln(b/a).

• PLL Lock Time

  Estimate the settling time of a phase-locked loop using the documented rule that lock takes roughly four time constants of the natural frequency in radians per second (4 divided by two pi times the loop bandwidth in Hz).