Resistor color code
Pick the band colors to read the value, or type a value to find out its colors.
How to read the color code
Through-hole resistors are too small to print readable numbers on, so their value is encoded with color bands according to the IEC 60062 standard. Each color stands for a digit from 0 to 9:
Black 0 · Brown 1 · Red 2 · Orange 3 · Yellow 4 · Green 5 · Blue 6 · Violet 7 · Gray 8 · White 9
On a 4-band resistor, the first two bands are significant digits, the third is the multiplier (the power of 10 to multiply by, in other words, how many zeros to add) and the fourth, set apart from the others, is the tolerance. For example, yellow-violet-red-gold is 4, 7 and two zeros: 4700 Ω = 4.7 kΩ with ±5%.
5-band resistors, usually metal film precision parts (1% or better), use three significant digits before the multiplier. Gold and silver as multipliers divide by 10 and 100 to give values below 10 Ω.
Why 4.7 kΩ and not 5 kΩ? The E series
Manufacturers do not make just any value, only those in the standard E series. The E12 series has 12 values per decade (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82), spaced logarithmically so that with a 10% tolerance the ranges of possible values touch each other without gaps. E24 adds intermediate values for 5% parts, and E96 covers 1% resistors.
Which end do you start reading from?
The tolerance band (usually gold or silver) tends to be set a little apart from the rest and goes on the right. If in doubt, remember that gold and silver are never the first digit, and that the value you get should belong to a standard series.
Frequently asked questions
How do you read a 4-band resistor?
The first two bands are the first two digits, the third is the multiplier (the number of zeros) and the fourth, set slightly apart, is the tolerance. For example, yellow-violet-red-gold is 4 and 7 followed by two zeros: 4,700 Ω, that is 4.7 kΩ with ±5 % tolerance.
What are the colours of a 10 kΩ or a 220 Ω resistor?
A 10 kΩ resistor is brown-black-orange (1, 0 and three zeros), and a 220 Ω resistor is red-red-brown (2, 2 and one zero). Other common ones: 1 kΩ is brown-black-red, 100 Ω is brown-black-brown and 4.7 kΩ is yellow-violet-red. All of them are followed by the tolerance band, usually gold.
What is the difference between 4, 5 and 6-band resistors?
5-band resistors use three significant digits instead of two, so they allow more precise values and usually have tolerances of 1 % or better. 6-band resistors add a final band for the temperature coefficient, in ppm/K, which tells how much the value drifts as it heats up.
What do the gold and silver bands mean?
In the tolerance position, gold means ±5 % and silver ±10 %. When they appear in the multiplier position they divide instead of multiply: gold is ×0.1 and silver ×0.01. So red-red-gold-gold is a 2.2 Ω resistor.