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Calculate Voltage Across a Component

Find the voltage drop across a resistor from current and resistance.

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.

Voltage Drop tips

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Enter current and resistance to get the voltage dropped across that component (V = I × R).

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In a series circuit the voltage drops add up to the supply voltage — handy for voltage dividers.

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Long thin wires have resistance too; significant drop there means you need a thicker gauge.

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Back to Ohm's Law Calculator