Using the model
Symbols, assumptions and limitations
Interpretation notes
The calculator assumes a resistive DC circuit and positive magnitudes.
Worked examples
See the method in practice
01
Voltage and resistance
A 12 V supply across 6 Ω produces 2 A and dissipates 24 W.
02
Power and resistance
A 100 W load with 25 Ω requires 50 V and draws 2 A.
Questions
Frequently asked
Which two values can I enter?
Any two among voltage, current, resistance, and power, provided they describe one resistive operating point.
Does this model AC circuits?
No. Reactive impedance, phase, and power factor require an AC circuit model.
Sources & review
Equations and examples are checked against the references below. Results are educational and should be independently verified for safety-critical work.
OpenStax University Physics — Ohm’s lawWritten by the STEM Hub editorial team · Reviewed August 11, 2026 · Review methodology