Ohm's Law Calculator
Uses voltage and resistance to estimate current and electrical power in a simple resistive circuit.
How it works
Uses voltage and resistance to estimate current and electrical power in a simple resistive circuit.
Formula and assumptions
Current = voltage ÷ resistance. Power = voltage² ÷ resistance. This assumes a positive resistance and a simple resistive load; real AC and reactive circuits may need RMS and power-factor calculations.
Example
Use the sample values, calculate, and change one input at a time.
Frequently asked questions
Are results exact? Results depend on the assumptions and inputs above.
Can I use this for professional decisions? Verify critical results independently.
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Frequently asked questions
What does it calculate?
It calculates current and power from voltage and positive resistance using Ohm’s law.
What should I check before relying on the result?
Confirm the input units and assumptions described above; independently verify safety-critical, medical, financial or professional decisions.