Capacitor Code Decoder

Understanding Capacitor Codes

Capacitor codes provide vital information about the capacitor’s capacitance, tolerance, and voltage rating. This guide will help you decode the information printed on capacitors.

Capacitance Value

The capacitance value of a capacitor is typically printed directly on its body in microfarads (µF), nanofarads (nF), or picofarads (pF). When space is limited, a numerical code is used.

The first two digits represent significant figures, and the third digit is the multiplier. For example:

• "104" translates to 10 (significant figures) and 4 (multiplier), meaning 100,000 pF or 100 nF or 0.1 µF.
• "472" translates to 47 (significant figures) and 2 (multiplier), meaning 4,700 pF or 4.7 nF.

For capacitance values below 10 pF, a different format using a letter "R" to denote the decimal point is sometimes used. For example:

• "1R5" means 1.5 pF
• "0R5" means 0.5 pF
• "4R7" means 4.7 pF

Small numbers without unit notation can indicate microfarad (µF) values. For example:

• ".1K63" represents 0.1 µF with a tolerance of ±10% and a voltage rating of 63 volts.
• "1K63" represents 1 µF with a tolerance of ±10% and a voltage rating of 63 volts.

Voltage Rating

The voltage rating, often indicated in volts (V), signifies the maximum voltage the capacitor can handle. This is sometimes directly printed on the capacitor. For example:

• "25V" means the capacitor can safely operate up to 25 volts.

EIA DC Voltage Codes

The Electronic Industries Alliance (EIA) uses a specific coding system to indicate the DC voltage rating of capacitors. For example:

• "0G": 4V
• "1A": 10V
• "1C": 16V
• "1E": 25V
• "1H": 50V
• "2A": 100V
• "2Q": 250V
• "2W": 450V

Tolerance

Tolerance indicates how much the actual capacitance can vary from the stated value. It is usually denoted by a letter code. For example:

• "J": ±5%
• "K": ±10%
• "M": ±20%

Practical Examples

Example 1: "473K 25V"

• Capacitance: 473 translates to 47,000 pF (47 followed by 3 zeros), which equals 47 nF or 0.047 µF.
• Tolerance: "K" indicates ±10%.
• Voltage Rating: 25V means the maximum voltage rating is 25 volts.

Example 2: "1R5K 50V"

• Capacitance: 1R5 means 1.5 pF.
• Tolerance: "K" indicates ±10%.
• Voltage Rating: 50V means the maximum voltage rating is 50 volts.

Example 3: "104K 2A"

• Capacitance: 104 translates to 100,000 pF (10 followed by 4 zeros), which equals 100 nF or 0.1 µF.
• Tolerance: "K" indicates ±10%.
• Voltage Rating: 2A is an EIA voltage rating indicating 100 volts.

Example 4: ".1K63"

• Capacitance: .1 represents 0.1 µF.
• Tolerance: "K" indicates ±10%.
• Voltage Rating: 63 volts.

Example 5: "6n8K63"

• Capacitance: 6n8 means 6.8 nF.
• Tolerance: "K" indicates ±10%.
• Voltage Rating: 63V means the maximum voltage rating is 63 volts.