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_aPower (mW)
power_mw = voltage_v * current_a * 1000Variables
| Variable | Description | Default |
|---|---|---|
voltage_v | Voltage Across Component(V) | 5 |
current_a | Current 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
- 01P = 5 x 0.1 = 0.5 W = 500 mW
- 02Ensure component is rated above 0.5 W.
Frequently Asked Questions
Why does it matter?
Excess heat damages components and reduces reliability.
How to reduce dissipation?
Lower voltage, reduce current, or use a more efficient component.
Safe margin?
Derate by 50%: use a 0.5 W resistor for 0.25 W dissipation.
Learn More
Guide
How to Calculate Power Consumption
Learn how to calculate electrical power consumption for circuits and devices. Covers watts, kilowatt-hours, efficiency, and practical tips for reducing energy use.
Ready to run the numbers?
Open Power Dissipation Calculator