Decode Resistance Value - Resistor Color Code Calculator
getcalc.com's Resistor Color Code Calculator is an online electrical engineering tool to calculate or decode resistance value based on the 4 color bands of resistors. Based on the composition of the material, the resistance value get changed largely. The below table of information shows the common materials and their corresponding resistance values used in the field of electrical & electronics engineering for various purposes. Any value of resistors can be represented by using this most reliable color coding method. Users may refer the below table to get familiar with the values of different colors used in the resistors and decode the actual resistor value by applying the values in the below formula.
| Common Materials & Resistance | ||
|---|---|---|
| Material | Resistance (Ω) | Usage |
| Silver | 1.64 x 10-8 | Conductor |
| Copper | 1.72 x 10-8 | Conductor |
| Gold | 2.45 x 10-8 | Conductor |
| Aluminium | 2.80 x 10-8 | Conductor |
| Carbon | 4 x 10-5 | Semi-conductor |
| Germanium | 47 x 10-2 | Semi-conductor |
| Silicon | 6.40 x 102 | Semi-conductor |
| Paper | 1010 | Insulator |
| Mica | 5 x 1011 | Insulator |
| Glass | 1012 | Insulator |
| Teflon | 3 x 1012 | Insulator |
To easily remember the color code values, memorize the below setence that is
”Black Brown ROY of Great Britain had a Very Good Wife who wore Gold and Silver Necklace“. Each marked alphabets & words in the sentence denotes the order of colors with their associated multiplier values. User may refer the below color band table & formula for more clarification.
Definition & Formula
Resistor Color Code is a popular technique used in electrical & electronic engineering to measure or decode the actual resistance value of a resistor in ohms, kilo-ohms, mega-ohms & giga-ohms. The 4 band color code is the most common & reliable color coding method to find the resistance value of a lead resistor. The A, B, C & Tolerance are the 4 color bands which represents the actual value of a resistor.
How to Decode Resistor Color Code?
The below example may help users to know how to calculate or decode the resistance value by using the color code of a resistor.
Example
Find the resistivity of a resistor having the color bands A as Green, B as Violet, C as Blue and Tolerance as Silver.
Solution
step 1
Address the formula, input parameters & values
Resistance Value (Ω) = AB x 10c ± Tolerance %
Band A = Green = 5
Band B = Violet = 7
Band C = Blue = 6
Tolerance = Silver = ± 10%
step 2
Apply the corresponding values in the resistance color coding formula
Resistance = 57 x 106 ± 10%
= 57000000 ± 10%
= 57 Mega ohm ± 10%
Step 3
Find the Tolerance
10% of 57 MΩ = (10/100) x 57000000
Tolerance = 5.7 MΩ
Step 4
Apply the tolerence in the formula
Resistance = 57 MΩ + 5.7 MΩ
= 62.7 MΩ
Resistance = 57 MΩ - 5.7 MΩ
= 51.3 MΩ
Thus, the resistance value of resistor varies between 51.3 MΩ and 62.7 MΩ
