Understanding the resistance color code is very important if you want to calculate the resistance values for a particular resistance. Each resistance ribbon represents a number where you can refer to the code below to help you find the default resistance value. The resistor coding acts as a resistor calculator and with given examples it would not take you very long to understand it.
0 = black, 1 = brown, 2 = red, 3 = orange, 4 = yellow, 5 = green, 6 = blue, 7 = violet, 8 = gray, 9 = white, gold = 5% and silver = 10%
Red, red, orange, gold = 22 times with 1 (orange equals three zero), so you get 22 times with 1000 = 22000 ohms or 22 kilograms with a tolerance of +/- 5% (gold).
Blue, gray, brown, gold = 68 times with 1 (brown equals a zero), so you get 68 times with 10 = 680 ohms with a tolerance of +/- 5%.
Brown, black, yellow gold = 10 times 1 (yellow equals four zero), so you get 10 times 10000 = 100000 ohms or 100 kilos ohm with a tolerance of +/- 5%.
Yellow, violet, gold, gold = 47 multiplied by 0.1 (gold by third band), giving you 4.7 ohm with a tolerance of +/- 5%
Orange, orange, silver, gold = 33 multiplied by 0.01 (third band silver), giving you 0.33 ohm with a tolerance of +/- 5%.
In electronic repair, I mostly encountered five band resistance color code. The purpose of using the five ribbon resistor in a circuit is to give it a more accurate value compared to the four ribbon. For example, to get the value 22.6kohm, with four color band resistance you will not be able to find it. The most you can get is 22k (red, red, orange and gold).
If you with the five color band will be able to calculate it (red, red, blue, red, brown), the last color that is brown represents 1% tolerance. If you open an analog multimeter, you will understand what I mean. Most of the resistance circuits inside the multimeter use five color bands. Why? Because the reading you get every time you measure current, voltage or ohms, the panel shows the closest value. For example, if you are measuring a 9V battery, the needle will point to, maybe 8.9v, 9v or 9.1 volts. If the particular multimeter was designed using four color band resistors, the result it can get is 8.5v, 9.5v or even 10 volts. In other words, the use of five ribbon resistors is to make a circuit more accurate and emit the desired result as what the engineers want it to be.
If you encounter a wirewound resistance, there are numbers printed on the resistance and each coding represents a resistance value. Below are the formulas you can use to find the exact resistance values: R82 is 0.82 ohms, 15R2 is 15.2 ohms, 100R is 100 ohms, 10K is 10 kilos ohms, 2K7 is 2.7 kilos ohms, and 2M2 is 2.2 mega ohms. Hope you find this resistor color code article useful and be able to calculate resistance value in the shortest amount of time.