Capacitor Code Calculator

About the Capacitor Code Calculator

Decodes the 3-digit code printed on ceramic capacitors into a capacitance value in picofarads, nanofarads and microfarads.

How to use this calculator

1. Enter the 3-digit capacitor code exactly as it appears on the capacitor.
2. Read the first two digits as the significant number.
3. Use the third digit as the number of zeros to add, which gives the value in picofarads, \(\text{pF}\).
4. Check the result, then convert it to other units if needed, such as \(\text{nF}\) or \(\mu\text{F}\).

The formula explained

The code gives the capacitance in picofarads by taking the first two digits as a number and multiplying by \(10^{\text{third digit}}\). So \(103\) means \(10 \times 10^3 = 10000\) \(\text{pF}\).

• code = the 3-digit capacitor code printed on the part
• \(d_1\) = the first digit of the code
• \(d_2\) = the second digit of the code
• \(d_3\) = the third digit of the code, which tells how many zeros to add
• C = capacitance in picofarads, \(\text{pF}\)

Step by step method

1. Take the first two digits and combine them into a number, \(10\) for the code \(103\).
2. Count the third digit as the number of zeros to add, so \(103\) means add \(3\) zeros.
3. Write the final capacitance in \(\text{pF}\), then convert if needed by using \(1000\) \(\text{pF} = 1\) \(\text{nF}\) and \(1000000\) \(\text{pF} = 1\) \(\mu\text{F}\).

Worked example

Problem. Decode the capacitor code \(104\).

1. The first two digits are \(10\).
2. The third digit is \(4\), so add \(4\) zeros, which gives \(100000\) \(\text{pF}\).
3. Convert if needed, \(100000\) \(\text{pF} = 100\) \(\text{nF} = 0.1\) \(\mu\text{F}\).

Tips and common mistakes

• The result is usually in picofarads, so do not forget to convert if the circuit uses \(\text{nF}\) or \(\mu\text{F}\).
• A code like \(101\) is not \(101\) \(\text{pF}\). It means \(10\) with \(1\) zero added, so \(100\) \(\text{pF}\).

Frequently asked questions