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Calculate Power Dissipation (Watts)

Find how many watts a component dissipates so you can size it safely.

Níl gá le logáil isteach
V
A
Ω
W
Enter any two values and the other two are solved automatically

💡 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

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Enter voltage and current (or resistance) and the power in watts is solved automatically.

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Resistors come in power ratings (1/4W, 1/2W, 1W…) — pick one rated well above the dissipated power.

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A part running near its power limit gets hot and ages fast; aim for at least 2× headroom.

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1
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