Calculate voltage, current, resistance, and power using Ohm's Law and electrical power formulas.
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Embed this ohm's law calculator on your website for free. It's responsive, always up-to-date, and easy to customize.
Enter any 2 values: Current + Resistance, Power + Current, or Power + Resistance
Select whether you want to find voltage, current, resistance, or power based on what values you know.
Input at least two known electrical parameters. The calculator needs minimum two values to solve for the others.
The calculator uses V = I × R and P = V × I relationships to find unknown values.
Get comprehensive results showing voltage, current, resistance, and power for your circuit.
Check that calculated values are within safe operating limits for your components and application.
Safe voltage levels for most applications. Common in electronics, automotive, and low-power systems.
Household and automotive voltage levels. Requires proper safety precautions and appropriate components.
Dangerous voltage levels requiring special safety measures, qualified personnel, and proper electrical codes compliance.
High current requires appropriate wire gauge, fuses/breakers, and thermal management to prevent overheating.
Enter any two of voltage, current, resistance, or power to solve the rest. Great for quick circuit checks and sizing components.
Solve any two to find the other quantities. Handy for electronics and power checks with quick unit awareness.
Compute V, I, R, P from any known pair.
Volts, amps, ohms, watts with quick tips.
Sizing resistors, checking loads, sanity checks.
Ohm's law calculator volts amps ohms watts electronics power
Pair with other electrical calculators.
Important: This Ohm's law calculator is designed for educational and basic electrical analysis purposes using fundamental electrical relationships and idealized circuit conditions. While calculations are mathematically accurate for basic DC circuits and resistive AC circuits, real-world electrical systems involve complex factors including temperature effects, reactive components, non-linear loads, and safety considerations that are not accounted for in simplified Ohm's law calculations. For electrical system design, troubleshooting, safety analysis, or any electrical work involving safety risks, always follow applicable electrical codes, use proper safety procedures, and consult qualified electricians or electrical engineers who can account for the specific complexities and safety requirements of your electrical application.