Ohm's Law Calculator

Solving for voltage: V = 12 V, I = 2 A, R = 6 Ω, P = 24 W.

How it works

• Applied Ohm's law V = I × R to the two known quantities.
• Derived the remaining quantity by rearranging the law.
• Computed the power with P = V × I.

V = I × R = 2 A × 6 Ω = 12 V

• Assumes a linear (ohmic) component at a constant temperature; real components drift with heat.
• Uses SI base units: volts, amperes, ohms and watts.

Methodology

1. Ohm's law: V = I × R, so any one of V, I or R follows from the other two.
2. Electrical power: P = V × I.
3. The tool applies the two relations in the selected mode and rounds the outputs to 12 significant digits.

Usage

1. Choose which quantity to solve for.
2. Enter the two known values among voltage, current and resistance.
3. Read the solved quantity, the full V/I/R/P set and the formula.

Examples

These are examples, not current values: they use fixed inputs, while the interactive tool computes live results in your browser.

Voltage from 2 A and 6 Ω

{
  "solveFor": "voltage",
  "voltage": 0,
  "current": 2,
  "resistance": 6
}

Current from 12 V and 6 Ω

{
  "solveFor": "current",
  "voltage": 12,
  "current": 0,
  "resistance": 6
}

Resistance from 12 V and 2 A

{
  "solveFor": "resistance",
  "voltage": 12,
  "current": 2,
  "resistance": 0
}

Power from 12 V and 2 A

{
  "solveFor": "power",
  "voltage": 12,
  "current": 2,
  "resistance": 0
}

Limitations

SI electrical units

The volt, ampere, ohm and watt are SI derived units. The ohm is defined as V/A, so Ohm's law V = I × R is exact in SI base units; the calculator simply rearranges it. Power is the product of voltage and current for a purely resistive (D.C.) load.