Power Dissipation Calculator Formula

Understand the math behind the power dissipation calculator. Each variable explained with a worked example.

Formulas Used

Power Dissipated

power_w = voltage_v * current_a

Power (mW)

power_mw = voltage_v * current_a * 1000

Variables

VariableDescriptionDefault
voltage_vVoltage Across Component(V)5
current_aCurrent Through Component(A)0.1

How It Works

Power Dissipation

P = V x I

Also: P = I^2 x R and P = V^2 / R.

All forms are equivalent via Ohm's Law.

Worked Example

5 V across a component at 100 mA.

voltage_v = 5current_a = 0.1
  1. 01P = 5 x 0.1 = 0.5 W = 500 mW
  2. 02Ensure component is rated above 0.5 W.

Ready to run the numbers?

Open Power Dissipation Calculator