How do you calculate voltage drop across a resistor? Physics Electrical Energy and Current Current and Resistance 1 Answer Douglas K. Mar 15, 2018 #V_"drop"=IR# where, #I#, is the current (in Amperes) through the resistor and, #R#, is the value of the resistor (in Ohms). Answer link Related questions When work is done on a positive test charge by an external force to move it from one location to... What is an electric circuit? What is Ohm's law? How does a battery produce electric energy? How does the electrical circuit in my flashlight work? What is a volt? How can I calculate resistance of a parallel circuit? How can i calculate resistance of a wire? How can i calculate voltage drop in a parallel circuit? How do you calculate voltage drop in a series circuit? See all questions in Current and Resistance Impact of this question 27699 views around the world You can reuse this answer Creative Commons License