Resistors come in a wide range of values, shapes, and sizes. Most leaded resistors with power ratings up to one-watt feature colored bands to indicate resistance value, tolerance, and occasionally the temperature coefficient. These resistors can have between three and six colored bands, with the four-band variety being the most common. The initial bands represent the digits of the resistance value, followed by a multiplier band that shifts the decimal point. The final bands indicate the tolerance and temperature coefficient.

Each color band represents resistance values, tolerances, and occasionally temperature coefficients. Understanding resistor color codes is simple once you grasp the meaning and calculations behind each band. We have prepared an easy-to-understand chart to help you decipher resistor color bands.

Identification of Color Ring Resistor

Identification method

The color value of the color ring resistor is usually black for 0, brown for 1, red for 2, orange for 3, yellow for 4, green for 5, blue for 6, purple for 7, grey for 8, white for 9, gold, and silver for the error value.

The first color ring (usually near the end of the resistor) indicates the first digit of the resistance value, the second color ring indicates the second digit of the resistance value, the third color ring indicates the third un-digit of the resistance value, the fourth color ring indicates the multiplier of the resistance value by a multiple of 10, and the fifth color ring indicates the error.

Identification order

First: Find the color ring that marks the error first, so as to arrange the order of the color ring. The most commonly used resistor error colors are gold, silver, and brown, especially gold and silver rings, generally rarely used as the first ring of the resistor color ring, so as long as there are gold and silver rings on the resistor, you can basically determine that this is the color ring resistor of the last ring.

Second: whether the brown ring is the error sign of the judgment. Brown ring is often used as an error ring, but also as a valid digital ring, and often in the first and last ring at the same time, making it difficult to identify who is the first ring. In practice, the interval between the color rings can be identified: the first few rings are almost close and equal spacing, and the last ring is relatively far from the previous ring, which can determine the order of the color ring.

Third: in the color ring spacing alone can not determine the order of the color ring, you can also use the production sequence of resistors to identify the value. For example, there is a resistor color ring reading order is: brown, black, black, yellow, brown, the value of 100 × 10,000 = 1MΩ error of 1%, belonging to the normal value of the series of resistors if it is the reverse order of reading: brown, yellow, black, black, brown, the value of 140 × 1Ω = 140Ω, the error of 1%. Obviously in accordance with the latter ordering of the resistance value read out in the production series of resistors is not available, so the latter color ring order is not correct.

How to read resistor color codes

Three or four-band resistors

The first two bands on three or four-band resistors represent the first two digits of the resistance value in ohms. On these resistors, the third band is the multiplier, which adjusts the decimal point to convert the value from megaohms to milliohms, or anywhere in between. The fourth band, if present, indicates tolerance. If there's no fourth band, as in the case of a three-band resistor, the default tolerance is ±20%.

Five or six-band resistors

High-precision resistors add an extra color band for a third significant digit. On five or six-band resistors, the third band represents this additional digit, while the fourth band becomes the multiplier and the fifth indicates tolerance. A six-band resistor is similar to a five-band one, but it includes an extra band that shows either reliability or the temperature coefficient (ppm/K). For example, if the sixth band is brown, a temperature change of 10°C would alter the resistance by 0.1%.

Frequently Asked Questions About Resistor Color Code:

What is the Resistor Colour Code?

Resistors are typically quite small, making it difficult to print resistance values directly on them. Instead, color bands are used to represent their electrical resistance. These bands are known as resistor color codes. The resistor color code system was developed in the 1920s by the Radio Manufacturers Association (RMA).

How do I know which end of the resistor to start reading from?

Many resistors have some of the ribbons clustered closer together or concentrated at one end. Place the resistor with these ribbons on the left side. Always read the resistor from left to right.

Resistors never come with metal rings from the left side. If your resistor has a gold or silver ring on one end, the resistor has a tolerance of 5% or 10%. Place the resistor with this ring on the right side and read the resistor from left to right again.

Base resistor values range from 0.1 ohms to 10 megohms. With this knowledge, it is clear that the third color on a four-ring resistor is always blue (106) or lower, and the fourth color on a five-ring resistor is always green (105) or lower.

Why aren't my high-voltage resistors metallic in color?

The gold and silver colors in the high-voltage resistors have been replaced by yellow and gray to prevent metal particles from appearing in the external coating.

What is a zero ohm resistor?

Easily recognized by their individual black bands, zero ohm resistors are basically wires used to connect lines on a printed circuit board. They are packaged in a similar way to resistors, so the same automated equipment used to place resistors can also be used to place them on circuit boards. This design avoids the need to use a separate machine to install jumpers.

What is a “reliability” band?

Military resistors typically include an additional ring on a four-ring resistor to indicate reliability or failure rate (%) per 1000 hours of service. This is rarely used in commercial electronics.