Resistor Color Code Guide

Check out the All About Circuits Resistor Color Code Calculator, a handy tool for reading resistor color code values.

Resistor values are often indicated with color codes. Practically all leaded resistors with a power rating up to one watt are marked with color bands. The coding is defined in the international standard IEC 60062, which describes marking codes for resistors and capacitors. In addition to defining the color bands, it includes numerical codes used for surface mount SMD resistors.

The color code is given by several bands. Together they specify the resistance value, the tolerance, and sometimes the reliability or failure rate. The number of bands varies from three to six. At a minimum, two bands indicate the resistance value and one band serves as multiplier. The resistance values are standardized; these values are called preferred values.

Resistor Color Code Chart

The chart below shows how to determine the resistance and tolerance for resistors. The table can also be used to specify the color of the bands when the values are known. An automatic resistor calculator can be used to quickly find the resistor values.

Tips for Reading Resistor Codes

The reading direction might not always be clear. Sometimes the increased space between bands 3 and 4 helps indicate the correct direction.
The first band is usually the closest to a lead. A gold or silver band (the tolerance) is always the last band.
Always check the manufacturer's documentation to confirm the color coding system used.
When in doubt, measure the resistance with an ohmmeter—especially when bands are faded or burnt.

4 Band Resistor

The four band color code is the most common. These resistors have two bands for the resistance value, one multiplier band, and one tolerance band.

Example: Green, Blue, Red, Gold

Green = 5
Blue = 6
Red = Multiplier (×100)
Gold = Tolerance (±5%)

Result: 56 × 100 = 5600 ? with 5% tolerance (range: 5320 to 5880 ?). If the tolerance band is absent, the tolerance is 20%.

5 Band Resistor

High precision resistors use a five-band code with an extra digit for resistance value.

Example: Brown, Yellow, Violet, Black, Green

Brown = 1
Yellow = 4
Violet = 7
Black = Multiplier (×1)
Green = Tolerance (±0.5%)

Result: 147 ? with 0.5% tolerance.

Note: In some cases, the extra band can indicate failure rate (military specification) or temperature coefficient.

6 Band Resistor

Used for high precision applications. Includes a sixth band for temperature coefficient.

Example: Orange, Red, Brown, Brown, Green, Red

Orange = 3
Red = 2
Brown = 1
Brown = Multiplier (×10)
Green = Tolerance (±1%)
Red = Temp Coefficient (50 ppm/°C)

Result: 3.21 k? with 1% tolerance and 50 ppm/°C temperature coefficient.

Reliability Band

Some resistors produced to military specs include an additional band indicating reliability, shown as failure rate per 1000 hours.

This is rarely used in commercial electronics and is typically found in four-band resistors. Refer to US MIL-HDBK-199 for more details.