Practical guide · 6 min read
Series vs Parallel Resistance
Recognize circuit arrangements and choose the correct equivalent-resistance equation.
Series components share one current path; parallel components share the same pair of nodes.
Series
Add resistor values directly. The equivalent resistance must be larger than every individual resistor.
Parallel
Add reciprocals, then take the reciprocal of the total. The equivalent must be smaller than the smallest branch.
Mixed networks
Reduce one recognizable group at a time and redraw the simplified circuit after every step.
Try the related calculator
Use the method above with an interactive tool that keeps the equation and units visible.
Open calculatorEditorial note
This guide is educational. Examples are deliberately compact and cannot cover every model, course convention, or laboratory condition. See our methodology for how formulas and examples are reviewed.