Resistor Parallel Calculator — InnovChip

Resistor Parallel Calculator

Find the equivalent resistance of up to four parallel resistors, plus branch currents for a given source voltage.

Calculator

About This Calculator

Parallel resistors share voltage but split current. The equivalent resistance is the reciprocal of the sum of reciprocals of each branch. Enter up to four resistors (enter 0 to skip a branch) and this calculator returns the total plus the current each active branch carries at your source voltage.

How to Use

  1. Enter the resistor values; set unused slots to 0.
  2. Set the source voltage across the parallel network.
  3. Read the equivalent resistance, total conductance and total current.
  4. Branch current per resistor is also shown for R1 and R2.

Formulas

Equivalent resistance1/R(eq) = 1/R1 + 1/R2 + 1/R3 + 1/R4
ConductanceG = 1/R, total G = Σ 1/Rn
Branch currentIn = V / Rn

Design Notes

For just two resistors: R(eq) = (R1·R2) / (R1 + R2).

The equivalent resistance of paralleled equal resistors is R/n — quick sanity check for your result.