basic

Power Dissipated in a Resistor Calculator

P = I²R = V²/R = IV — Joule heating.

Calculates power dissipated P using any two of V, I, R: P = V²/R = I²R = V·I. Also computes the energy dissipated over a given time and required resistor wattage rating.

Nadia Almasri By Nadia Almasri
Published Last reviewed 1 min read

Inputs

V
Ω
s

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

P = V²/R = I²R = V·I

In depth

Calculates power dissipated P using any two of V, I, R: P = V²/R = I²R = V·I. Also computes the energy dissipated over a given time and required resistor wattage rating.