Current through a 470Ω resistor at 12V
Worked answer for 12V applied across a 470Ω resistor, using Ohm's law (I = V/R) and power (P = V²/R).
Current 25.5 mA 12V ÷ 470Ω · dissipates 306 mW
| Voltage (V) | 12 V |
| Resistance (R) | 470Ω |
| Current I = V / R | 25.5 mA |
| Power P = V² / R | 306 mW |
Driving 12V through 470Ω gives 25.5 mA of current (I = V/R) and the resistor must dissipate 306 mW of heat (P = V²/R). Pick a resistor power rating comfortably above that figure.
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Open the Ohm's Law Calculator →Disclaimer: This is a reference estimate using ideal Ohm's law. Real components have tolerance and self-heating; verify against your part's datasheet and power rating before building.