Find the equivalent of two resistors in series (sum) or parallel (reciprocal sum).
| Req (Ω) | – |
Use this calculator for two resistors: series Req = R1 + R2 (same current) or parallel 1/Req = 1/R1 + 1/R2 (same voltage).
Two 100 Ω in parallel behave like 50 Ω. Capacitors swap the rules (series reciprocal, parallel sum). More than two resistors, or a mix of series and parallel, need to be reduced in steps.
R₁ (Ω): First resistor, in ohms.
R₂ (Ω): Second resistor, in ohms.
Connection: Series adds. Parallel shares voltage.
Req (Ω): Equivalent resistance.
Related calculators