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.

Source resistance

Required number input.

Find the load resistance in ohms that absorbs maximum power from a source, equal to the source resistance by the maximum power transfer theorem. 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]

Load for maximum power

The resulting load for maximum power 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.

• Max Power Delivered

  Compute the maximum power in watts deliverable to a matched load from a Thevenin equivalent source.

• Max Resistance

  Compute the maximum resistance as nominal ohms times (1 + tolerance percent / 100).

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  Maximum-power-point current from measured maximum output power and voltage at that same operating point.