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Parallel Resistors Calculator

Equivalent resistance of resistors in parallel.

R1
R2
R3
Equivalent resistance
56.897 Ω
1 / R = sum(1 / Ri)

Parallel resistance is always less than the smallest resistor. Series resistance is the simple sum.

About

Add resistor values, get the parallel resistance: 1/R = 1/R1 + 1/R2 + ... Useful for designing circuits or matching to a needed resistor value when you don't have the right one in your kit.

How to use

  1. Add each resistor value.
  2. See the equivalent resistance.

FAQ

What about series?+

Series is just addition. R = R1 + R2. Toggle the mode to switch between parallel and series.

Why is parallel always smaller than the smallest?+

Adding paths for current to flow lowers total resistance. Two equal resistors in parallel give half the value.