Calculate voltage, current, resistance, or power using Ohm's Law. Enter two values to solve for the others.
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Enter Your Measurements
Results
Current
2.000
A
Power
240.00
W
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Formula
V = IR | P = VI = V²/R = I²R
How to Use This Calculator
How to Use
- 1
Enter voltage in volts.
- 2
Enter resistance in ohms.
- 3
Get current in amps and power in watts.
Frequently Asked Questions
Frequently Asked Questions
What is Ohm's Law?
Ohm's Law states that current (I) equals voltage (V) divided by resistance (R): I = V/R. It describes how voltage, current, and resistance relate in a conductor.
How do I calculate watts from volts and amps?
Power (W) = Voltage (V) × Current (A). A 120V outlet drawing 10A uses 1,200 watts = 1.2 kW.
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About This Calculator
This calculator uses the formula: V = IR | P = VI = V²/R = I²R. All calculations follow industry-standard methods. Results are estimates — always verify with a licensed professional for structural or code-compliant work.
Built and maintained by the CalcSmart team. Last updated March 2026.
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