Ohms Law Calculator

Our Ohm’s Law calculators enable you to easily obtain unknown values in the Ohm’s Law equations simply by providing any two known values. In resistive circuits, this allows you to determine the relationship between power, resistance, current, and Voltage.

Simply enter any two known values into the respective tool, be it for resistance or power, below, press "calculate", and Ohm's Law will determine the remaining value.

In this formula for Ohm’s Law:

V = I * R

V = Voltage, measured in Volts (V)

I = Current, measured in Amps (A)

R = Resistance, measured in Ohms (Ω)

As Ohm’s Law states that V = I * R, for a given constant Voltage, higher resistance entails a lower flow of current. The reverse is equally true as well. The higher the current flow, the lower the resistance for the constant Voltage. This is represented visually by the Ohm’s Law triangle you can see at the top of the calculator.

Our second Ohm’s Law calculator utilises the equation:

P = V * I

Whereby:

P = Power, measured in Watts (W)

V = Voltage, measured in Volts (V)

I = Current, measured in Amps (A)

You can use our calculator above to work out the remaining value depending on the two known values, employing the Ohm’s Law formulas.

Ohm’s Law describes the connection between resistance, current, and Voltage simply by stating that the current flowing through a conductor is directly proportional to potential difference between two points. In many materials, this holds true at a variety of currents and Voltages.

Essentially, Ohm’s Law states that the Voltage difference between two points, the electric current flowing between those points, and the resistance along the current path are all related and proportional. The Voltage difference across the terminals of a two-terminal device such as a fixed resistor directly affects the current passing across the device.

No matter whether the current or driving Voltage is time-varying (AC) or constant (DC), Ohm's Law applies to circuits that contain only resistive elements - so no inductors or capacitors. We can express it using several equations as outlined above and depicted in the Ohm’s Law triangle.

Disclaimer: The information provided by this digital calculator is intended for general guidance purposes only. While we strive for accuracy, we advise users to consult the manufacturer's technical specification sheets for detailed and precise information. We cannot guarantee the completeness or reliability of the data presented here. For specific applications and critical decisions, always refer to the official technical documentation provided by the manufacturer.