Resistors are very small, so colour bands provide a simple standard way to show their marked resistance value.
The colours carry information.Learn the basics
Resistor Colour Codes
Those coloured bands on a resistor are not decoration. They tell us the resistor’s value.
Let’s learn how to read them one step at a time.
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Why coloured bands?
Start with why resistors use colours instead of printed numbers.
For a standard 4-band resistor: Band 1 is the first digit, Band 2 is the second digit, Band 3 is the multiplier, and Band 4 is the tolerance.
Two digits. Multiplier. Tolerance.
The first two bands follow a fixed number order from Black = 0 through White = 9.
The colour order follows 0 to 9.
The third band tells us what to multiply the first two digits by. In the common 0–9 colour sequence, it can also be understood as how many zeros follow them.
Red multiplier = ×100, so 10 × 100 = 1,000 Ω.
The third band scales the number.
Real resistors are not always exactly the marked value. The tolerance band tells us how far the actual resistance may vary.
1,000 Ω ±5% means the actual value can be roughly between 950 Ω and 1,050 Ω.
Tolerance tells us the possible variation.
Brown – Black – Red – Gold gives the digits 10, then the Red multiplier ×100: 10 × 100 = 1,000 Ω.
Gold gives ±5% tolerance, so the final value is 1,000 Ω ±5%, or 1 kΩ ±5%.
Read the digits first, then the multiplier, then the tolerance.
BBROY of Great Britain had a Very Good Wife.
The capital letters help you remember the resistor colour order: B = Black = 0, B = Brown = 1, R = Red = 2, O = Orange = 3, Y = Yellow = 4, G = Green = 5, B = Blue = 6, V = Violet = 7, G = Grey = 8, and W = White = 9.
The first letters help you remember the colours, and the colours follow the number order from 0 to 9.
Remember the phrase first. The numbers follow the colour order.Resistor colour codes in simple words
- Band 1 gives the first digit.
- Band 2 gives the second digit.
- Band 3 gives the multiplier.
- Band 4 gives the tolerance.
- The colour values run from Black = 0 to White = 9.
- Use “BBROY of Great Britain had a Very Good Wife” to remember the order.