Resistor Color Coder

Resistance is futile.

A simple, effective resistor color coder.

Designed with students, teachers, and engineers in mind for iPhone and iPad.
Easily and effectively identify resistances and tolerances.

periodic Table iPhone

Intuitive Design.

The Resistor Color Coder is designed to be straightforward and painless to use.

Comprehensive Information.

All digits of the resistor - first, second, multiplier, and tolerance - are available to help you understand exactly how the resistor color coder calculations work.

Thorough Explanations.

Every step of calculating the resistance is written out in an informative manner.


Resistance Calculation.

The resistance is calculated any time a band color is changed. The actual digit values are also displayed, in case you want to calculate it out manually (or are just curious!).

Tolerance Calculation.

The tolerance is automatically calculated when a band is selected.


A complete, guided explanation on how to calculate resistance is included - in case you ever run out of battery unexpectedly ;).

Fun Fact.

A fun fact about resistor color codes is included!