How do I read a 3-digit capacitor code?

The first two digits are significant figures and the third is the number of zeros, giving a value in picofarads. A code of 104 is 10 followed by 4 zeros = 100 000 pF = 100 nF = 0.1 µF.

What does the tolerance letter mean?

It encodes the allowed deviation: J is ±5%, K is ±10% and M is ±20% are the most common, with finer letters like F (±1%) for precision parts.

What does a 2-digit capacitor code like 47 mean?

A 1- or 2-digit code is a direct value in picofarads, so 47 simply means 47 pF. The multiplier rule only applies to 3-digit codes.

What is the value of a 104 capacitor?

104 means 10 × 10⁴ = 100,000 pF, which equals 100 nF or 0.1 µF — one of the most common decoupling capacitor values.

Is anything uploaded?

No — the calculation runs entirely in your browser, nothing is sent anywhere.

Capacitor Code Calculator

Small ceramic capacitors are too tiny to print a full value, so they use a 3-digit code instead. This calculator decodes that code into capacitance in picofarads (pF), nanofarads (nF) and microfarads (µF), and interprets the optional tolerance letter. It is built for hobbyists and electronics engineers reading parts off a board or a bag of components.

How it works

For a 3-digit code, the first two digits are the significant figures and the third is the power-of-ten multiplier (the number of trailing zeros), giving a value in picofarads:

value (pF) = first two digits × 10^(third digit)

A 1- or 2-digit code is read directly as picofarads (47 = 47 pF). The optional trailing letter is the EIA tolerance code, where J = ±5%, K = ±10% and M = ±20% are most common, and finer letters like F (±1%) mark precision parts. The tool then converts the pF value into nF (÷ 1,000) and µF (÷ 1,000,000).

Example

Decode 104J:

Step	Value
Significant figures	10
Multiplier	10⁴ (four zeros)
Capacitance	100,000 pF = 100 nF = 0.1 µF
Tolerance (J)	±5%

So a capacitor marked 104J is 0.1 µF ±5%. Everything is computed in your browser, nothing uploaded.