Boneyard Tools

Capacitor Code Calculator

Type a printed capacitor code such as 104 to read its capacitance in picofarads, nanofarads and microfarads, including the tolerance from a trailing letter.

How to read a capacitor code

  1. Enter the code printed on the capacitor, for example 104 or 104K.
  2. The first two digits are significant figures and the third is a power-of-ten multiplier.
  3. Read the value in pF, nF and uF, plus the tolerance if a letter is present.

Examples

Common 104 code

code = 104
100000 pF = 100 nF = 0.1 uF

Small value 479

code = 479
4.7 pF (47 x 0.1)

Frequently asked questions

How do I read a 3-digit capacitor code?

The first two digits are significant figures and the third is the number of zeros to add, giving the value in picofarads. So 104 is 10 followed by four zeros, 100000 pF.

What does the 104 capacitor code mean?

104 means 10 x 10^4 picofarads, which is 100000 pF, or 100 nF, or 0.1 uF. It is one of the most common ceramic capacitor values.

What about 2-digit codes?

Codes with one or two digits are the value in picofarads directly. For example 10 means 10 pF and 47 means 47 pF.

Why do some codes end in 8 or 9?

The multipliers 8 and 9 are special: 8 means x0.01 and 9 means x0.1. So 479 is 47 x 0.1 = 4.7 pF, used for very small capacitors.

What does the letter after the code mean?

A trailing letter is the tolerance. Common ones are J for +/-5%, K for +/-10% and M for +/-20%. The tool shows the matching tolerance.

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