Ohm's Law Calculator

Voltage (V)  V = I x R

Current (I)  I = V / R

Resistance (R)  R = V / I

Ohm's Law Calculation Result:
____ will cause
____ to flow through
(The power dissapated in the resistance is ____)

Calculations you've done so far:


Ohm's Law describes the relationship between voltage, current and resistance. It can be applied to the electrical behavior of conductors and insulation so it's often used in cable testing. This calculator is designed to help you learn more about the interaction of voltage, current, and resistance.

Ohm's Law describes one possible relationship between voltage and current. The law is written mathmatically as:

V = I * R I = V / R R = V / I

Where V is voltage, I is current, and R is resistance. Ohm's Law says the voltage across a resistance is proportional to the current flowing through that resistance.

On this calculator you:
    1) Enter any two of three values (V, I, and R),
    2) Click "Calculate",
    3) The third value will be displayed in the Ohm's Law Calculation Result section.

Also see our calculator for Ohm's Law Calculator for High Voltage Testing.

Note: This general purpose calculator can generate combinations of voltage and current that are not practical in normal cable testing applications. If the calculation shows voltages or currents that are out of the specified range for a cable tester then you know the tester doesn't measure the resistance with the current or voltage you've selected.