Ohm’s Law is a fundamental electrical formula used to calculate the relationship between voltage, current and resistance in a circuit. It states that voltage equals current multiplied by resistance, and understanding this equation is key in electronics, PCB design, troubleshooting and hobby projects.
This Ohms Law Calculator lets you enter any two values and automatically solves for the others. You can quickly find voltage, current, resistance or electrical power based on what information you already have. Ideal for engineers, students and makers who need fast circuit math.
I = V ÷ R
R = V ÷ I
P = V × I
Using Ohm’s Law makes circuit planning easier, whether you are sizing resistors, calculating load on a power supply or checking safe current limits for components. Power calculations help determine heat dissipation and ensure components are operating within safe ratings.