Quick answer: use Ohm's Law (V = I × R) and the power formula (P = V × I) to convert between volts, amps, watts, and ohms. Try our free Voltage and Power Converter.
The Core Formulas
Ohm's Law: Voltage (V) = Current (I) × Resistance (R). Power: Watts (P) = Voltage (V) × Current (I). Rearranging these lets you solve for any missing value given the other two.
Practical Example
A 120V device drawing 5 amps uses 120 × 5 = 600 watts. This is how you'd check if a device fits within a circuit's power rating.
Frequently Asked Questions
How do I find watts if I only know volts and resistance?
First find current using I = V/R, then calculate power using P = V × I.
Is this safe to use for home electrical work?
This tool helps with calculations, but always consult a licensed electrician for actual home electrical work.
What's the difference between AC and DC calculations here?
These are basic DC formulas; AC circuits involve additional factors like power factor for more complex calculations.
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