Voltage Drop Calculator
Calculate the voltage drop across each resistor in a series or parallel circuit. Enter the supply voltage and add your resistor values.
V
R1
Ω
R2
Ω
| Resistor | Voltage drop | Current |
|---|---|---|
| R1 = 220 Ω | 4.800 V | 21.82 mA |
| R2 = 330 Ω | 7.200 V | 21.82 mA |
| Total | 12.000 V | 21.82 mA |
How voltage drop is calculated
In a series circuit, the total resistance is the sum of all resistor values. The current is the same through each resistor, calculated as I = V / Rtotal. The voltage drop across each resistor is V = I × R.
In a parallel circuit, the voltage across each resistor equals the supply voltage. The current through each branch is I = V / R for that resistor.