# Ohm's Law Calculator

> Calculate voltage, current, resistance, and power from a selected known pair.

Page: https://askcalculators.com/calculator/ohms-law-calculator/
Definition: https://askcalculators.com/calculator/ohms-law-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/ohms-law-calculator/schema.json
Version: 1.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/ohms-law-calculator/?knownPair=voltageResistance&firstValue=12&secondValue=6

## Inputs
- knownPair: Known values; type=select; required; default=voltageResistance; values=voltageResistance|voltageCurrent|currentResistance|powerVoltage|powerCurrent|powerResistance
- firstValue: First selected value; type=number; required; default=12; min=1e-9
- secondValue: Second selected value; type=number; required; default=6; min=1e-9

## Outputs
- power: Power; format=number; primary
- voltage: Voltage; format=number
- current: Current; format=number
- resistance: Resistance; format=number

## Formula
V = IR; P = VI = I²R = V²/R

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: Use proper electrical safety procedures and rated equipment.