MihsabaHow to use
This tool calculates equivalent resistance for the same resistor list in series and in parallel. Series resistances add directly; in parallel, conductances 1/R add and the result is inverted. Inputs can be in Ω, kΩ or MΩ.
- Enter 1–100 positive resistor values separated by commas or spaces.
- Choose the unit shared by all values.
- Calculate both series and parallel equivalents.
How it is calculated
Example
Example: 100Ω, 220Ω and 330Ω give 650Ω in series. In parallel the equivalent is about 59.19Ω, below the smallest branch resistance.
Important notes
This calculator handles all-series or all-parallel networks, not arbitrary mixed circuits. It uses nominal resistance values and does not model component tolerance, power rating or temperature effects.
Frequently asked questions
Why is parallel resistance below the smallest resistor?
Adding a parallel path increases total conductance, so equivalent resistance decreases.
What about equal resistors?
N equal resistors R give NR in series and R/N in parallel.
Does this calculate current and power?
No. This tool focuses on equivalent resistance; use the Ohm’s law calculator for voltage/current/power relationships.
Is this calculator free?
Yes. It is free to use and requires no account.