Science

Ohm's Law Calculator

Calculate Voltage, Current, Resistance, and Electric Power with Ohm's Law.

Reviewed & Maintained by

Aadil Malik — Software Engineer

1 min read · 24 words

What is an Ohm's Law Calculator?

An Ohm's Law calculator computes Voltage ($V$), Current ($I$), Resistance ($R$), and Power ($P$) in DC circuits.

Frequently Asked Questions

Ohm's Law states that electric current through a conductor between two points is directly proportional to voltage across the points: V = I * R.

Voltage (V in Volts), Current (I in Amperes), Resistance (R in Ohms Ω), and Power (P in Watts).

Power is the rate of electrical energy transfer: P = V * I = I² * R = V² / R.

In series circuits, current is constant and resistances add (R_total = R1 + R2). In parallel circuits, voltage is constant and reciprocal resistances add.

Ohmic materials maintain constant resistance over voltage changes (resistors). Non-ohmic materials change resistance with temperature or voltage (diodes, incandescent bulbs).

Color bands represent digits, multipliers, and tolerance percentages.

DC (Direct Current) flows in one constant direction. AC (Alternating Current) periodically reverses direction.

Due to Joule heating ($P = I^2 R$), where electrical resistance dissipates energy as heat.