Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's Law (V = IR) and the power formula (P = VI).

Solve For

Voltage
12.0000 V

Formulas

FormulaExpression
VoltageV = I × R
CurrentI = V / R
ResistanceR = V / I
Power (1)P = V × I
Power (2)P = V² / R
Power (3)P = I² × R

All Values

Voltage (V)
12.0000 V
Current (I)
2.0000 A
Resistance (R)
6.0000 Ω
Power (P)
24.0000 W
QuantityValue
Voltage (V)12.0000 V
Current (I)2.0000 A
Resistance (R)6.0000 Ω
Power (P)24.0000 W
Power (kW)0.024 kW
Energy (kWh/hr)0.024 kWh

Calculate voltage, current, or resistance using Ohm's Law with our free calculator, essential for basic electronics and circuit analysis.

How It Works

Ohm's Law: V = I × R, where V is voltage (volts), I is current (amps), and R is resistance (ohms). This calculator rearranges the formula to solve for any variable given the other two.

How to Use This Calculator

  1. Select what you want to calculate (voltage, current, or resistance)
  2. Enter the two known values
  3. Click Calculate to see your result

Frequently Asked Questions

What is Ohm's Law used for?

It's a fundamental relationship in electronics used to design circuits, calculate power requirements, and troubleshoot electrical problems.

How is power related to Ohm's Law?

Power (watts) = Voltage × Current (P = VI), and can also be expressed using Ohm's Law substitutions as P = I²R or P = V²/R.

Does Ohm's Law apply to all electrical components?

It applies to "ohmic" components (like standard resistors) where resistance stays constant; some components (like diodes) are non-ohmic and don't follow a simple linear V=IR relationship.

What happens to current if resistance increases (voltage constant)?

Current decreases proportionally, since I = V/R, higher resistance restricts current flow for a given voltage.