Physics & Electrical calculator

Ohm's Law Calculator

Choose the value to solve, enter the other two measurements and see the complete V = I × R relationship.

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No account. Formula and assumptions are shown below.

Calculator inputs

Ohm's law details

Formula & disclaimer

Voltage = Current × Resistance; Power = Voltage × Current

View assumptions

Formula reviewCalcs at Hand Editorial TeamVerified 31 August 2026 · automated checks included

Three useful checks, kept deliberately short.

What this result includes

The circuit voltage is 12 V and electrical power is 24 W.

A practical example

A circuit carries 2 A through 6 Ω: Multiply current by resistance · Calculate voltage · Multiply voltage by current for power.

Common input mistake

Real components may change resistance with temperature, frequency or operating conditions.

Voltage = Current × Resistance; Power = Voltage × Current

Ohm's law describes an ideal resistive relationship between voltage, current and resistance.

Keep in mind: Use rated component values and safe test procedures. De-energise circuits before resistance measurements.

Produced byCalcs at Hand Editorial Team

Last formula check31 August 2026

Review methodKnown examples + boundary cases