Resistor color code calculator

 

This resistor color code calculator will help you determine the value of axial resistors marked with color bands. It can be used for 3, 4, 5 and 6 band resistors. You can select the colors of the corresponding bands by clicking on them in the table. The resistor will visually show your band color choices and display the value of the resistor above. If the resistance value is part of a standard E-series value, this will be shown in brackets after the resistance value. How to use the color code calculator Select the amount of bands of the resistor on the top-left Choose the colors of the bands by clicking on the corresponding box in the chart The corresponding ohmic value and tolerance of the resistor is shown Bands: 3 4 5 6 10k&#8486 ±5% 1st digit 2nd digit 3rd digit multiply tolerance TCR(ppm/K) Bad Black 0 0 0 1 1% (F) 100 Beer Brown 1 1 1 10 2% (G) 50 Rots Red 2 2 2 100 15 Our Orange 3 3 3 1K 25 Young Yellow 4 4 4 10K Guts Green 5 5 5 100K 0.5% (D) But Blue 6 6 6 1M 0.25% (C) 10 Vodka Violet 7 7 7 10M 0.1% (B) 5 Goes Gray 8 8 8 100M 0.05% (A) Well White 9 9 9 1G Get Gold 0.1 5% (J) Some Silver 0.01 10% (K) Now None 20% (M) Special cases 6 band resistors In the case of 6 band resistors, this calculator assumes the 6th band is used to indicate the thermal coefficient. In some rare cases the 6th band can also indicate the reliability of the resistor. For more information visit the main page on the resistor color code. Disclaimer While we did our best to check all possibilities and remove [… read more]

Resistor color code

 
Resistor color code

How does the resistor color code work? Resistor values are often indicated with color codes. Practically all leaded resistors with a power rating up to one watt are marked with color bands. The coding is defined in the international standard IEC 60062. This standard describes the marking codes for resistors and capacitors. It includes also numerical codes, as for example often used for SMD resistors. The color code is given by several bands. Together they specify the resistance value, the tolerance and sometimes the reliability or failure rate. The number of bands varies from three till six. As a minimum, two bands indicate the resistance value and one band serves as multiplier. The resistance values are standardized, these values are called preferred value. Resistor color code chart The chart below shows how to determine the resistance and tolerance for resistors. The table can also be used to specify the color of the bands when the values are known. An automatic resistor calculator can be used to quickly find the resistor values. Tips for reading resistor codes In the sections below examples are given for different numbers of bands, but first some tips are given to read the color code: The reading direction might not always be clear. Sometimes the increased space between band 3 and 4 give away the reading direction. Also, the first band is usually the closest to a lead. A gold or silver band (the tolerance) is always the last band. It is a good practice to check the manufacturer’s documentation to be sure about the used coding system. Even better is to measure the resistance with a multi-meter. In some cases this might even be the only way to figure out the resistance; for example when the color bands are burnt off. 4 band resistor The [… read more]

Resistance of a resistor

 
Resistance of a resistor

Resistance of a resistor The function of a resistor is to oppose the electric current through it. This is called electrical resistance, and is measured in the unit ohm. The resistance can be calculated with Ohms law, when the current is known and the voltage drop is measured:     The resistance of a resistor is dependent on its material and shape. Some materials have a higher resistivity, causing a higher value. The value is often printed on the resistor with a number or in the form of a color code. What is resistance? The concept of current, voltage and resistance can be explained by a hydraulic analogy. A flow of water through a pipe is restricted by a constriction. This causes a pressure drop after the constriction. The flow of water is equivalent to electric current. The pressure drop is equal to the voltage drop. The constriction is equivalent to the resistor, and has a certain resistance. The resistance is proportional to the voltage or pressure drop for a given current. In the hydraulic example, the resistance can be increased by for example reducing the diameter of the constriction. For a resistor or wire, the resistance is in general dependent on the material and the geometrical shape. The influence of the geometrical shape, can easily be explained by using the hydraulic example. A long and narrow tube will have a higher resistance than a short and wide tube. The resistance property of a material is called resistivity. The electrical resistance of a resistor is proportional to the resistivity of the material. For a rectangular cross-section resistor the resistance R is given by: where ρ is the resistivity of the resistor material (W·m), l is the length of the resistor along direction of current flow (m), and A is the [… read more]