This app recommends resistors for you to combine in parallel to create a very precise resistance value. It works iteratively by calculating the best resistor value to add based on the measured values of resistors you’ve previously added. You can usually get within 1% of your target with 2 or 3 resistors.

It is useful for when you have a collection of resistors and don't want to order a specific value in because you are limited in time or designing something on the fly.

A resistor color chart is included for convince when you are searching through your pile of resistors. You will also find a help section, tips section, and complete working usage example included in the app.

This app is free and open source software: https://github.com/tannercollin/exact-resistor-calculator