Equivalent Resistance

Compute equivalent resistance of resistors in series or parallel; with source voltage also output total current.

Inputs

Formula

Series R = ΣRi; Parallel 1/R = Σ(1/Ri)

How to use

  1. Fill in Connection, Resistor R1, Resistor R2, Resistor R3, Resistor R4, Source U (opt.) in the Inputs section (watch the unit on each field).
  2. Click Calculate; the tool evaluates the formula shown above.
  3. Read Equiv. R_eq, Total current I in the results area.
Formula notesSeries R_eq = Σ R_i; parallel 1/R_eq = Σ(1/R_i); two in parallel R_eq = R₁·R₂/(R₁+R₂).