Series Resistor Calculator
Add up to fifty positive resistor values and review equivalent resistance, count and entered range.
What would you like to do next?
Add resistor values connected in one series path
Paste or type positive resistance values separated by commas, spaces or lines. The calculator adds them to produce ideal equivalent resistance, counts the components and displays the smallest-to-largest entered range. A list input is faster to audit than a fixed set of boxes and supports both a short classroom circuit and a longer prototype chain without uploading any design data.
Check tolerance, power and hidden resistance
Series resistance is an arithmetic sum only when the same path passes through each component. Real results can also include lead, trace, connector and contact resistance. Evaluate component tolerance and temperature coefficient, then calculate current and individual power dissipation before selecting parts. This page does not confirm a safe voltage or power rating.
Frequently asked questions
How many resistors can I enter?
The browser accepts from one through fifty positive values.
Do series resistances always add?
Yes for ideal resistors connected along the same current path.
Are tolerance and power rating included?
No. Review actual component specifications and circuit current separately.