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# Capacitor Code: Color and Alphanumeric Value Coding

In this article, we'll examine the capacitor code used to indicate the value of capacitors. Capacitors are tiny passive electronic components that store electric charge when there is a potential difference across their terminals. And although there are several types of capacitors, all have the general equation C=Q/V. So their coding standard is the same. You can measure their capacitance using a multimeter, but capacitor color and alphanumeric codes are faster. So read on to learn more!

## Capacitor Code: Color

Capacitor color band coding resembles the one used in resistors, where each band color represents a different value. This capacitor color coding follows the spectral order, and there can be up to five bands per capacitor. The first and second colors denote the initial capacitance digits. But the third indicates the multiplier, while the last two show the tolerance and voltage, respectively. Some capacitors don’t have tolerances, meaning they will have four colored bands. Here’s a summary of the data the color codes imply.

### Capacitance Capacitor Color Coding Table

If you have a keen eye, you must have noticed the voltage variable missing from the table. And it is not by accident. The capacitor band-color voltage rating depends on the capacitor type. Manufacturers simplify the type labeling using the following references.

Different capacitor types

The last color band of the four or five bands in a capacitor indicates the voltage, and the color coding refers to these values.

### Capacitor Color Code Example

Here’s an example for better understanding. Let’s say you have a polyester or polystyrene capacitor with five color bands in this order.
• Yellow
• Red
• Orange
• White
• Red
As the first color, yellow indicates the first number (four). The next number is two, followed by the multiplier (x1,000). These readings are in pF, so we have 42x1,000pF so far. The result is 42000pF or 42nF. Since this capacitance is higher than 10pF, the tolerance is +/-10%. If it were lower than 10pF, the tolerance would be +/-1.0pF. Lastly, the voltage is 250V because we are dealing with a Type L capacitor. So it can operate safely for voltages up to 250V.

A summary of the capacitor color coding

## Capacitor Code: Alphanumeric Characters

If you look at most modern circuit boards, they don’t have color-coded capacitors. This labeling system became obsolete many years ago, so you will probably only find such components in old electronics. Modern capacitors use alphanumeric character coding, which consists of three digits and one letter at the end.

Ceramic disc capacitors with 3-digit codes

But some have the capacity printed directly on the case. For instance, you might see 1000µF 6.3V. This labeling implies it has a 1000µF charge capacity and can operate safely at voltages not exceeding 6.3V. However, if you encounter the alphanumeric code, here’s what the characters mean.
• 1st and 2nd numbers give the capacitance in pF
• 3rd number is the multiplier (usually in the range of 0-6)
• The last letter indicates the tolerance
Manufacturers usually use this format for low-capacitance units.

An electrolytic capacitor with the capacitance and voltage printed on the walls

Let’s say you have a capacitor written 404J. The first two numbers indicate the capacitance, which is 40pF. The third number (4) is the multiplier. So the value so far is 40x104=400,000pF (400nF or 0.4µF). And J is the tolerance, which is +/-5%.

### Letter Tolerance Code Table

The most typical tolerance coding is the following. You can reverse engineer the coding if you have a known capacitance value and tolerance. For instance, if a capacitor has a value of 1.5µF with a +/-20% tolerance, you can calculate its coding as follows. First, convert the capacitance to pF, which will be 1.5x1,000,000=1,500,000pF Next, take the first two numbers (15) to be the first in the code. The multiplier should result in 100,000 because this capacitance is the same as 15x100,000. So it is 105, meaning the third number is five. The final alphanumeric character (letter) will be M to match the +/-20% tolerance. So the code will be 155M.

### Voltage Code

Unlike color coding, this alphanumeric value does not cover the voltage. So if not indicated, you might notice the alphanumeric code underlined, usually on brown-colored capacitors. This mark means the maximum voltage is 50/100V. If not underlined, the voltage rating is 500V. But if the component does not have this capacitor voltage code, check the documentation to get the exact figure.

### Operating Temperature Range Code

In addition to the 3-digit capacitor code, some ceramic disc capacitors have black marks at the top. This code denoted the component’s operating temperature range, usually -25 to 85°C.

### Polarity

Most capacitors don’t have polarities except the electrolytic type. So you must check the positive and negative labeling on the case before soldering or connecting it to your circuit.

An electrolytic capacitor

## Wrap Up

Experts like to use coded wordings for standardization, and the same applies to electronics engineers when labeling capacitors. But if you’ve gone through the article to this point, you must have realized that the capacitor code values are simple to decipher. Some even have the capacitance value written on the case, meaning you don’t have to interpret anything. So understanding capacitor values is relatively straightforward. And that’s it for this article. Comment below if you need further clarification. We’ll be happy to help.