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Capacitor Code Calculator

Type a printed capacitor code such as 104, 223, 4R7 or 104K to read its capacitance in pF, nF and µF.

How to use this calculator

  1. Type the code printed on the ceramic capacitor (e.g. 104, 223, 4R7 or 104K).
  2. The value in pF, nF and µF appears instantly, with the tolerance letter if present.

How capacitor codes work

Small ceramic capacitors are marked with a 3-character code. The first two digits are the significant figures and the third is the number of zeros (the power-of-ten multiplier), giving a value in picofarads (pF):

104 → 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 µF

A letter R stands for a decimal point (so 4R7 = 4.7 pF). One- and two-digit codes are read directly in pF. A trailing letter indicates the tolerance.

LetterToleranceLetterTolerance
B±0.1 pFJ±5%
C±0.25 pFK±10%
D±0.5 pFM±20%
F±1%Z+80% / −20%
G±2%

Common codes

CodeCapacitance
1021 nF
10310 nF
104100 nF (0.1 µF)
1051 µF
22322 nF
47347 nF

Frequently asked questions

What does 104 mean on a capacitor?
10 followed by 4 zeros in picofarads: 100,000 pF = 100 nF = 0.1 µF.
What does the K mean, like in 104K?
The trailing letter is the tolerance — K means ±10% (J is ±5%, M is ±20%).
How do I read 4R7?
The R is a decimal point, so 4R7 = 4.7 pF.

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