How it works
Series equivalent R=R1+R2. Parallel equivalent R=1/(1/R1+1/R2).
Input definitions
- First resistance (Ω)
- Enter the value in the labeled unit.
- Second resistance (Ω)
- Enter the value in the labeled unit.
- Connection
- Choose Series / Parallel.
A worked example
- First resistance (Ω)
- 100
- Second resistance (Ω)
- 200
- Connection
- Series
Assumptions & limits
Two ideal positive resistors. Excludes tolerance, temperature dependence and power ratings. Not an electrical installation design.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Will two resistors in parallel always have lower resistance?
For positive ideal resistances, the parallel equivalent is smaller than either resistor. Series resistance is their sum. Tolerance and heat limits are outside this calculation.
Does this replace a circuit or electrical safety assessment?
No. The result uses the idealized model shown. Component tolerance, temperature, fault conditions and installation requirements need separate evaluation.
How does the Series and parallel resistor network tool work?
Series equivalent R=R1+R2. Parallel equivalent R=1/(1/R1+1/R2).
What are the assumptions and limits of Series and parallel resistor network?
Two ideal positive resistors. Excludes tolerance, temperature dependence and power ratings. Not an electrical installation design.