Resistor Colour Code Calculator

Number of Bands

Band #1

Band #2

Band #3




What Are Resistor Colours?

Resistors use coloured bands to signify the value of the resistor and the colour-coding system dates back to the early 20th century when electronic components were first being mass-produced.

At that time, printing numbers or values directly onto small components was challenging and often impractical. Colored bands provided a simple, space-efficient way to convey information.

Colour bands are easily distinguishable and can be read from any angle, making it straightforward for technicians and engineers to identify resistor values quickly. This is particularly useful during assembly, troubleshooting, and repair of electronic devices.

Why Do Resistors Use Colour Codes?

Modern electronics demand compact, lightweight components. The colour bands on resistors allow for a clear display of resistance values without increasing the physical size of the component.

Printing text or numbers directly on small resistors would require larger components or advanced printing techniques, which could complicate the design and increase costs.

Unlike printed numbers that can fade or smudge over time, the paint used for these bands is often designed to withstand environmental factors such as heat, humidity, and mechanical abrasion.

This ensures the longevity of the markings, making them reliable throughout the resistor's lifespan.