Resistor color bands

The colored bands on resistors indicate their electrical value and tolerance, following a universally standardized code.

About this subject

Resistors are passive electronic components that limit current flow in circuits. Their resistance is measured in ohms, and to facilitate identification without instruments, a color code is used consisting of painted bands on the component body. This system was developed in the early 20th century and globally adopted by the electronics industry.

The most common resistor color code uses 4 bands: the first two represent the first two digits of the value, the third is the multiplier (number of zeros), and the fourth indicates tolerance. For example, a resistor with bands brown (1), black (0), red (x100), and gold (±5%) has a value of 1000 ohms (1 kΩ) with 5% tolerance. There are also 5- and 6-band resistors, including a third digit or temperature coefficient.

Standardization is defined by international standard IEC 60062, specifying colors for each digit: black (0), brown (1), red (2), orange (3), yellow (4), green (5), blue (6), violet (7), gray (8), and white (9). For multipliers, additional colors like silver (x0.01) and gold (x0.1) are used in precision resistors. Tolerance is indicated by a gold (±5%), silver (±10%), or no band (±20%).

Although modern components often use numeric markings or SMD codes, resistors with colored bands are still widely used in prototyping, educational kits, and hobbyist equipment. Learning to read these bands is a fundamental skill for electronics enthusiasts, allowing quick identification of values without a multimeter and preventing assembly errors.

Frequently Asked Questions

How do you read a 4-band resistor?

The first two bands indicate digits, the third is the multiplier, and the fourth is tolerance. Use the color chart: black=0, brown=1, red=2, orange=3, yellow=4, green=5, blue=6, violet=7, gray=8, white=9. Multiplier: black=×1, brown=×10, red=×100, etc. Tolerance: gold=±5%, silver=±10%, no band=±20%.

What is the difference between 4-, 5-, and 6-band resistors?

4-band resistors have precision of ±5% or ±10%. 5-band resistors add a third digit for higher precision (±1% or ±2%). 6-band resistors include a band for temperature coefficient, used in applications requiring thermal stability.

Why are the colors standardized internationally?

To ensure resistors manufactured in any country can be identified in the same way, facilitating trade and circuit assembly. The IEC 60062 standard unifies the color code and is recognized globally.