Circuit Resistance Calculator

Series: R_total = R1 + R2 + R3... Parallel: 1/R_total = 1/R1 + 1/R2 + 1/R3...

What this calculator does

3 × 100Ω in series = 300Ω. Same 3 in parallel = 33.3Ω.

Frequently asked questions

How do you add resistors in parallel?

1/Rtotal = 1/R1 + 1/R2 + ... Or for two resistors: Rtotal = (R1 × R2)/(R1 + R2).