Capacitor Marking Decoder

What code 104 or 4n7 on a capacitor means: decoding into picofarads, nanofarads and microfarads.

Common codes

CodepFnFµF
100100.010.00001
1011000.10.0001
1021,00010.001
10310,000100.01
104100,0001000.1
1051,000,0001,0001
220220.0220.000022
2212200.220.00022
2222,2002.20.0022
22322,000220.022
224220,0002200.22
4714700.470.00047
4724,7004.70.0047
47347,000470.047
474470,0004700.47
68368,000680.068

Tolerance letters

LetterTolerance
B±0.1 pF
C±0.25 pF
D±0.5 pF
F±1%
G±2%
J±5%
K±10%
M±20%
Z+80% / −20%
How the code works

Three digits: the first two are the value, the third is the number of zeros, and the result is in picofarads. 104 = 10 with 4 zeros = 100,000 pF = 100 nF = 0.1 µF. Letter-as-point notation: 4n7 = 4.7 nF, 2u2 = 2.2 µF, 470p = 470 pF. A plain two-digit number is just picofarads: 47 = 47 pF.

Electrolytic

capacitors are labelled directly: capacitance in µF and working voltage (e.g. 470 µF 25 V). Polarity matters - the negative lead is marked with a stripe on the body.

See also