Calculate Voltage Across a Component
Find the voltage drop across a resistor from current and resistance.
💡 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
Enter current and resistance to get the voltage dropped across that component (V = I × R).
In a series circuit the voltage drops add up to the supply voltage — handy for voltage dividers.
Long thin wires have resistance too; significant drop there means you need a thicker gauge.
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