Resistors in Series & Parallel Calculator
Resistor calculator: total resistance of resistors in series and in parallel.
Rs = Σ Ri · 1/Rp = Σ 1/Ri
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
In series resistances add: R = R₁ + R₂ + …. In parallel the reciprocals add, so the total is smaller than the smallest resistor.
Write values like 4.7k or 1M.
Frequently asked questions
100 Ω and 100 Ω in parallel?
50 Ω.