Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law
Formula
Ohm's Law:
$$V = I \times R$$
Power Formulas:
$$P = V \times I = I^2 R = \frac{V^2}{R}$$
About this Calculator
Ohm's Law is the fundamental relationship between voltage, current, and resistance in electrical circuits. This calculator lets you compute any value given the other two, plus calculates power using multiple formulas.
How to Use
- Enter any two known values (voltage, current, or resistance)
- The calculator computes the third value using Ohm's Law
- Power is calculated using all three power formulas
- Results update in real-time as you adjust sliders
Frequently Asked Questions
What is Ohm's Law?
Ohm's Law states that current through a conductor is directly proportional to voltage and inversely proportional to resistance. It's expressed as V = IR, where V is voltage in volts, I is current in amperes, and R is resistance in ohms.
When does Ohm's Law not apply?
Ohm's Law applies to 'ohmic' materials where resistance is constant. It doesn't apply to diodes, transistors, or non-linear components where resistance varies with voltage or current.
How do I calculate power?
Power (in watts) can be calculated three ways: P = V×I (voltage times current), P = I²R (current squared times resistance), or P = V²/R (voltage squared divided by resistance). All three give the same result.
