Resistorcalc.org is an intuitive online Resistor Replacement Calculator designed to simplify the process of finding equivalent resistor configurations for your electronic projects.
Whether you are an engineer, technician, or electronics enthusiast, this tool helps you identify practical resistor combinations that achieve your desired resistance value, saving you time and money.
It supports standard E-Series resistor values ranging from E12 to E96, covering a wide spectrum of tolerance options, so you can select the best fit for your precision needs.

Key USPs include its ability to quickly generate multiple solutions involving series, parallel, and mixed configurations, each with detailed accuracy percentages.
The calculator also provides clear circuit diagrams and well-explained formulas, such as series resistance, parallel resistance, and combo arrangements, enhancing your understanding.
Its fast computation engine ensures you get comprehensive results instantly, ideal for both prototyping and troubleshooting.
This free, professional-grade tool is developed by experienced electronics engineers—making it an essential resource for designing reliable circuits while optimizing cost and component use.