What this calculator actually models
Ohm's Law relates voltage, current and resistance with V = I × R. Once voltage and current are known, electrical power follows from P = V × I. Enter any two positive values and the calculator derives the other two.
How to use this calculator
Enter any two known positive values among volts, amps, ohms and watts.
Leave the other two fields empty.
Review all four calculated quantities and the input pair used.
Where people use it
- •Electronics and DC circuit checks
- •Sanity-checking equipment nameplate relationships
- •Electrical training and formula verification
Example: 12 V and 6 Ω
Current is 12 ÷ 6 = 2 A. Power is 12 × 2 = 24 W.
Assumptions and limits
- •This ideal calculation treats resistance as purely resistive. AC impedance, phase angle, inrush current and nonlinear loads require additional information.
- •Do not use a simple Ohm’s Law result alone to select protective devices, conductor sizes or certify code compliance.
Frequently asked questions
What is Ohm's Law?+
The basic relationship is V = I × R, where V is volts, I is amps and R is ohms.
Why does the calculator ask for two values?+
Two independent positive quantities are enough to solve the remaining voltage/current/resistance/power relationships for a simple resistive circuit.
Does this calculate AC impedance?+
No. This page is an ideal resistive Ohm/Watt law calculator, not a full complex-impedance solver.
Semantic next steps
Continue the calculation
These links move to a different input, formula or project stage rather than a keyword variation of this page.
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