Ohm's Law Calculator: Voltage, Current, and Resistance
Ohm's law ties three circuit quantities in one triangle. Given any two, this calculator finds the third.
What is the Ohm's Law Calculator?
Pick which quantity to find, then enter the other two. Ohm's law says voltage equals current times resistance, so the tool rearranges it as needed. It assumes an ohmic conductor at steady temperature.
How to use it
- Pick the quantity to solve for.
- Enter the other two values.
- Click Calculate.
Worked example
With current 2 A and resistance 6 ohms, voltage is 12 V.
What voltage is 2 A through 6 ohms?
12 volts, from current times resistance.
Frequently asked questions
Does it work for all circuits?
It assumes an ohmic conductor; some components, like diodes, do not follow Ohm's law.
What if resistance is zero?
Current would be undefined in the formula, so the tool asks for a non-zero value.