With this resistor color code calculator, you can calculate values of 3, 4, 5, and 6 band resistors. Also, this calculator will calculate the tolerance of the resistor by giving minimum and maximum values.
How to use it for finding the value of resistor:
Follow the following steps to find the value of a resistor
- Select the number of bands by observing bands on your resistor.
- Pick the column colors by observing band colors on your resistor.
By selecting the right color printed on the resistor you can find the value of the resistor.
Why Color Coding is used for Resistors:
Color coding is used to indicate the value of resistor in the easiest way. The value of resistance may vary with external factors also they come in very small sizes, we can not give the exact value of a resistor in numbers. color bands are very convenient, cheap, and easy method to show the rating of a resistor. Color coding is also used for capacitors, inductors, and diodes.
But when the size of the resistor is large enough their value like resistance, wattage and tolerance is printed on the surface. SMD resistors use a different alphanumeric coding system to indicate their values.
The coding for resistors is defined in the international standard IEC 60062:2016
. It describes the coding standard for resistors as well as capacitors.
How to Read value of resistor by Color Codes:
A resistor usually has three to six bands to show its values resistance, tolerance, and Temperature coefficient. Usually, the bands are read from left to right. The tolerance band is usually at the very right and it is slightly thicker than others bands.
Due to tolerance, we can't get the exact value of the resistor, so use a multimeter to get a more precise reading. Gold and Silver colors are used to represent tolerance. Gold and Silver are used to represent 5% and 10% tolerance respectively.
In the case of a three-band resistor, first, two bands represent first two significant digits and the third band indicates multiplier. As there is no tolerance band tolerance is always ±20%.
Four band resistors are more common in these resistors first two bands are the first two significant digits and the third band is multiplier and 4th band is the tolerance band.
In a five-band resistor, the first three bands represent three significant digits. The fourth band represents the multiplier and the fifth band is tolerance.
A six-band resistor is similar to a five-band resistor plus an extra 6th band is present to indicate the temperature coefficient of resistance (TCR)
What is Tolerance?
Tolerance is the percentage of error between the actually measured value and the expected value (Here in this case it is resistance). This happens due to the manufacturing process and it is expressed in percentage.
Calculating The Value of Resistance:
Calculating The Value of Resistance
write the value of the first two or three significant digits and then multiply it with the multiplier value. this gives us the expected value of the resistor.
After this we multiply the resistance value by the tolerance percentage, then we add and subtract that value from the actual value to get the minimum and maximum value of the resistance.
Consider a four-band resistor, the first two bands are Green and Black indicates the significant digits. By above rule 50
We multiply this number by the multiplier indicated with the 3rd orange band.
50x103 = 50000
the final value of the resistor will be,
50 x 1000 = 50000Ω = 50kΩ.
The fourth gold band shows tolerance of ±5%
Finally calculating range:
Minimum = 50000 - (50000 x 5/100) = 50000 - 2500 = 47500 = 47.5kΩ
Maximum = 50000 + (50000 x 5/100) = 50000 + 2500 = 52500 = 52.5kΩ
There is a zero-ohm resistor having a single black band, Its resistance is nearly zero and it is used to connect two traces on a PCB board. Resistors used for military purposes may have an extra band indicating the failure rate.