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What Is the Multiplier on Resistors?

Resistors are one of the most commonly used electronic components and are present in nearly every electronic circuit to control the flow of voltage or current. Resistors are available in a wide range of different resistances, measured in ohms, ranging from zero ohms through to values in the mega ohm range. As resistors are physically small, their values are denoted by a series of colored bands indicating the resistance and tolerance.

The Resistor Color Code
- The value of each resistor is printed on its body using four, five or six colored bands. Recognized internationally, this code uses either two or three bands to indicate the value. The next band indicates the multiplier value, which increases by a factor of 10 for each color, and ranges from 1 to 10,000,000, which represents 10 Mega ohms. Combining these bands allows the resistor value to be calculated. Two extra colored bands may be present to indicate the tolerance and temperature coefficient.
Four Colored Bands
- To read a resistor with four colored bands, first turn the resistor so that the colored stripe on one end of the resistor is on the left, as this is the first band. Look up the color of the band on a resistor color chart to determine the value, for example, a red band indicates 2. Look up the value of the second band to determine the second digit, and the third band to find the multiplier. The fourth band indicates the tolerance, which indicates how close to the marked resistance the real resistance is. For example, a resistor with the bands: red, red, yellow, silver would translate to 2, 2, x 10K = 220K. The silver band indicates a tolerance of +-10%, so the actual value of the resistor will be between 198K and 242K.
Five Colored Bands
- Reading a five-color resistor is similar to the four-band system, except the first three bands represent the digits, allowing for greater precision. The multiplier is represented by the fourth band, and the tolerance by the fifth band. For example, a resistor with the bands: blue, grey, black, red, gold indicates 6, 8, 0, x 100 = 68,000 ohms or 68K. The gold stripe indicates a tolerance of 5 percent. Most modern resistors now use the system of five colored bands to represent the value and tolerance.
Six Colored Bands
- If a resistor has six colored bands, the first three bands represent the digits, the fourth band the multiplier and the fifth band the tolerance. The sixth band represents the temperature coefficient of the resistor, for applications where accuracy is important. As an example, a resistor with the colored bands: yellow, violet, black, orange, brown, red has the value 4, 7, 0, x 1K = 470K. The brown band indicates a tolerance of 1 percent, and the final red band indicates a temperature coefficient of 50ppm.

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