Ohm's Law Calculator

Calculate voltage, current, resistance, or power from common Ohm’s law relationships.

Electrical engineering safety note

Electrical engineering calculators on ToolsBing are preliminary educational and planning tools only. Electrical work can create shock, fire, arc-flash, equipment damage, and code-compliance risks. Verify all calculations with licensed electricians, qualified engineers, manufacturer data, local electrical codes, protective-device requirements, and safety standards before installation or operation.

Enter electrical engineering inputs

Estimated result

ResultWaiting for input

W / Ω context

ConfidencePlanning estimate

Use for education, early planning, and comparison only.

Next stepCheck code and protection

Verify conductor ratings, breaker/fuse sizing, derating, grounding, environment, and local code requirements.

Formula and assumptions

Ohm’s law: V = I × R; P = V × I

This calculator uses simplified electrical assumptions. Real systems may require derating, conductor temperature ratings, insulation type, installation method, short-circuit protection, coordination studies, power quality review, and licensed professional verification.