Physics

Series Parallel Resistance Calculator

Equivalent resistance series and parallel for up to 3 resistors.

Free to use — no sign-up or login.

Series (Ω)

Parallel (Ω)

This free Series Parallel Resistance Calculator covers Equivalent resistance series and parallel for up to 3 resistors.

Series adds; parallel uses reciprocal sum. Related physics tools sit beside How it works, with no account required.

Using the Series Parallel Resistance Calculator

Equivalent resistance series and parallel for up to 3 resistors. Typical inputs are R1 (Ω), R2 (Ω) and R3 (Ω, 0=skip). How it works beside the form states the identity the Series Parallel Resistance Calculator applies.

FAQ

How do I use the Series Parallel Resistance Calculator?

Open the Series Parallel Resistance Calculator, fill R1 (Ω), R2 (Ω) and R3 (Ω, 0=skip), and read the result. Enter R1 (Ω), R2 (Ω), and R3 (Ω, 0=skip) for the Series Parallel Resistance Calculator; use finite values in the indicated domain. The calculator reports Series (Ω) and Parallel (Ω): Series adds; parallel uses reciprocal sum. Resistances should be nonnegative, and zero-ohm parallel branches need special handling.

What formula does the Series Parallel Resistance Calculator use?

The Series Parallel Resistance Calculator uses the identity in How it works. In words: Enter R1 (Ω), R2 (Ω), and R3 (Ω, 0=skip) for the Series Parallel Resistance Calculator; use finite values in the indicated domain. The calculator reports Series (Ω) and Parallel (Ω): Series adds; parallel uses reciprocal sum. Resistances should be nonnegative, and zero-ohm parallel branches need special handling.