About Ohm's Law & DC Power Calculator
Instantly solve circuit voltage (V), electric current (I), impedance or resistance (R), and dissipated electrical power (P). Enter any two known engineering parameters to solve the remaining two variables using the comprehensive Ohm's wheel relations.
Key Capabilities & Features
- Enter any 2 known values to solve remaining 2 variables
- Calculates Volts (V), Amperes (A), Ohms (Ω), and Watts (W)
- Provides full Ohm's wheel mathematical relations and derivation formulas
- 1-Click quick presets for residential 120V circuits and 240V heavy loads
- Copy specifications to clipboard with formatted SI engineering units
How to Use Ohm's Law & DC Power Calculator
Provide Known Parameters
Enter any two values among Voltage, Current, Resistance, or Power.
Automatic Resolution
The engineering engine instantly determines and applies the correct algebraic formulas.
Review & Copy
Inspect the resulting electrical properties, power dissipation in kW, and copy specs.
Privacy & In-Browser Execution Guarantee
100% client-side calculation. Circuit parameters and engineering formulas execute purely in your browser without telemetry.
Frequently Asked Questions
What is Ohm's Law formula?
Ohm's Law states that electric current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R): V = I · R. Combined with Joule's law, electrical power is P = V · I = I² · R = V² / R.
Can I calculate AC circuits with this tool?
For purely resistive AC loads with a unity power factor (PF = 1.0), Ohm's Law applies directly with RMS voltage and current values. For reactive AC loads, use the AC Power Calculator.