Calculate Power Dissipation (Watts)
Find how many watts a component dissipates so you can size it safely.
💡 Ohm's law: V = I × R. Power adds P = V × I. Knowing any two lets you derive the rest — handy for sizing resistors, checking LED current, or working out heat dissipation.
Power tips
Enter voltage and current (or resistance) and the power in watts is solved automatically.
Resistors come in power ratings (1/4W, 1/2W, 1W…) — pick one rated well above the dissipated power.
A part running near its power limit gets hot and ages fast; aim for at least 2× headroom.
نحوه کار
چرا ابزار ما؟
Also check out…
Size a Current-Limiting Resistor for an LED
Work out the resistor value an LED needs from supp
Solve Ohm's Law Homework
Check circuit problems by entering any two known v
Estimate Current Draw from a Battery
Find the current a load pulls so you can estimate
Calculate Voltage Across a Component
Find the voltage drop across a resistor from curre