EMBEDDED TOOL

Series/Parallel Resistor Calculator

Combine any number of resistor values in series or parallel.

Series total

Parallel total

Count

About this tool

Enter any number of resistor values (one per line) and instantly get both the series total (simple sum) and the parallel total (reciprocal sum) — handy for combining standard values to hit a target resistance, or checking a hand calculation.

Frequently asked questions

How is the parallel total calculated?
Using the general reciprocal formula 1/R_total = 1/R1 + 1/R2 + ... + 1/Rn, which works for any number of resistors, not just two.
Can I mix units like kΩ directly?
Enter everything in the same unit (typically ohms) — this tool treats every number as a plain value in ohms, so convert kΩ/MΩ values to ohms first (e.g. 4.7k → 4700).
What happens if I enter a 0Ω value?
It's included as-is in the series sum (adding nothing) but is skipped in the parallel calculation, since a 0Ω resistor in parallel would short the whole combination to 0Ω — the hint will flag this.