Resistors and the Color Codes

Although the color code is not only for resistors, the ability to read the resistor color code is more required among engineers and scientists. This convenient index was created by Radio Manufactures Association (now part of Electronic Industries Alliance) in early 1920s. It is hard to tell some of colors and which side should indicates the tolerance. In fact, the tolerance of resistors in the 4th or 5th bands are sometimes distinguished by spacing or width of the band. This page provides how you read the 4th-, 5th-, and 6th-band resistor color codes, and the related information on resistors.
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Four-band resistor color codes

        (PDF file for 4-band color codes)
4-band resistor color code

Example: (four bands)
example
Yellow, Green, Orange, Silver
Yellow and green represent 4 and 5, respectively. Those consist of the first and second digits, so it will be 45. The third band is orange. As a multiplier, it is × 1000, so you will calculate 45 × 1000; therefore, the resistance is 45,000 Ω. The forth band, silver, represents the tolerance, so the final expression of the resistance is 45,000 ± 10% Ω.

hint:
resistor color code
Problem 1:
resistor color code problem 1
Red, Green, Red, Gold
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω)
Problem 2:
resistor color code problem 2
Brown, Yellow, Blue, Gold
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω)
Problem 3:
resistor color code problem 3
Green, Violet, Blue, Silver
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω)

Five-band resistor color codes

        (PDF file for 5-band color codes)
5-band resistor color code

Example: (five bands)
example
Yellow, White, Yellow, Brown, Gold
Yellow, white and yellow represent 4, 9 and 4, respectively. Those consist of the first, second and third digits, so it will be 494. The forth band is brown. As a multiplier, it is × 10, so you will calculate 494 × 10; therefore, the resistance is 4,940 Ω. The fifth band, gold, represents the tolerance, so the final expression of the resistance is 4,940 ± 5% Ω.

hint:
colors
Problem 1:
resistor color code problem 4
Red, Violet, Blue, Blue, Gold
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω)
Problem 2:
resistor color code problem 5
Green, Grey, Green, Red, Silver
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω)
Problem 3:
resistor color code problem 6
Yellow, Black, Blue, Red, Gold
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω)

Six-band resistor color codes

        (PDF file for 6-band color codes)
6-band resistor color code

Example: (six bands)
6-resistor
Violet, Grey, Green, Red, Silver, Brown
Violet, grey and green represent 7, 8 and 5, respectively. Those consist of the first, second and third digits, so it will be 785. The forth band is red. As a multiplier, it is × 100, so you will calculate 785 × 100; therefore, the resistance is 78,500 Ω. The fifth band, silver, represents the tolerance, 10%. The sixth band is the temperature coefficient of the resistor. Brown represents 100ppm/K. Namely, the final expression of the resistance is 78,500 ± 10% Ω with Temp. Coeff. 100 ppm/K.

hint:
colors
Problem 1:
resistor color code problem 7
Blue, Green, Yellow, Blue, Gold, Yellow
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω) with Temperature Coefficient ppm/K
Problem 2:
resistor color code problem 8
Red, Grey, Violet, Yellow, Gold, Orange
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω) with Temperature Coefficient ppm/K
Problem 3:
resistor color code problem 9
Green, Orange, Blue, Yellow, Silver, Red
What is the resistance? (Type only numbers, no comma, no symbol.)
± % (Ω) with Temperature Coefficient ppm/K


Mnemonics


Each color corresponds to a certain number:
Black Brown Red Orange Yellow Green Blue Violet Grey White
0 1 2 3 4 5 6 7 8 9
There are several mnemonics for this. Some of statements might not be politically correct.

  • Better Be Right Or Your Great Big Venture Goes West


  • Bad Beer Rots Our Young Guts, But Vodka Goes Well


  • Black Bears Run Over Yellow Grass, But Vultures Glide over Water


  • Big Bears Run Over Your Gladiola Bed Vexing Gliarden Worms


  • Black Bugs Race Over Yellow Grass, Beside Violent Grey Water


  • Go to the top of this page


    Various resistors and the properties

    There are many types of resistors for various uses.

    Film type resistors

    These resistors are made from small rods of ceramic coated with resistive materials. The rough value of resistance is determined by the shape of the core material; then, a thin spiral groove cut by a laser or diamond cutter on the surface adjusts the fine value of resistance. It is attached to metal caps with leads, and coated with an insulated layer to be completed as a retailing resistor.

    film resistor mechanism

    Wirewound type resistors

    The resistors are made with a ceramic or glass rod, an insulator and resistive wire, such as the alloy of Nickel and Chromium (Nichrome) or the alloy of Copper, Nickel, and Manganese (Manganin). The value of resistance is adjusted by the amount of the wire wound around the ceramic or glass rod. The values of resistance are normally small and they are easy to be heated; however, they can deal with large amounts of electricity due to heat-resistant holders.

    wirewound mechanism

    Multiple type resistors

    The resistor contains multiple resistors with multiple leads. It is convenient to use it when multiple resistors have to be connected to multiple terminals in a limited room on a bread board.

    The independent resistor array contains each separated resistor. The bussed resistor array contains connected resistors with one common terminal as shown in the figure.

    SIP resistor array

    DIP resistor array

    Other types of resistors