Power & current / FORMULA-BASED TOOL

Ohm’s law calculator

Find voltage, current, resistance and power in a DC resistive circuit.

01Your inputs

Example values are prefilled. Replace them with your own.

V

DC voltage across the resistor.

Ω
02The working, shownΩ
Ω

Every result has a reason.

Enter your values and calculate to see the result, formula and working here.

V = I × R

Within this model

Steady DC through a positive, constant, ohmic resistance. Uses magnitudes. This model does not describe reactive AC loads or a complete installation.

UNDERSTAND THE CALCULATION

What the numbers mean.

Ohm’s law relates voltage across a resistor to current through it. Choose the two quantities you know. Power is calculated from voltage multiplied by current. Temperature changes and non-ohmic components can change the relationship.

Formula reference: Fluke · Ohm’s law

A worked example

A 12 V potential difference across 6 Ω gives 2 A. The resistor dissipates 24 W.

Validation, precision and limitations