A DC-DC converter includes a chip including an error amplifier, a pulse width modulator (PWM), and an inductor driven by said PWM in series with an output node (VOUT), wherein a load current flows through the inductor. A circuit for sensing the load current includes a first operational amplifier and a sense resistor having resistance RSENSE; wherein a sense current related to the load current flows through the sense resistor. A reference resistor has a resistance RREFERENCE which is a fixed multiple of RSENSE. A set resistor has a resistance RSET. Tracking circuitry sets a voltage across the reference resistor to be equal to a voltage across the set resistor. A function block receives a current through the set resistor and a current through the reference resistor to find their ratio. A current multiplier provides a measurement current which is proportional to the load current divided by RSET.