# Ceramic capacitors: how to read 3-digit plus 1-letter markings?

It seems that reading a ceramic capacitor value out of its written values is harder than decoding enigma machine.

I wonder if experienced users here does have a trick to quickly figure out these values. Some examples:

I know that 103M is 0.01µF but how does one figure this out? Another example 104Z/LK ...this one I cant get it at all. All I know is that Z is for assymetric capacitors with tolerence between 80% and -20% ... Am I right? If not would be nice to correct me and tell me where these Z ceramic capacitors are used mostly?

• Related question: electronics.stackexchange.com/questions/18102/… Aug 11, 2011 at 23:10
• Have you ever tried decoding messages encrypted with Enigma? I suspect Alan Turing would disagree with your assertion. ;) Aug 12, 2011 at 3:26
• Haha ofcourse not! Aug 13, 2011 at 15:33

The numbers work like a resistor.

The first two numbers are just numbers.

The third number is the number of 0's after. It's in picofarads.

So:

• 103 is 1 0 000 or 10,000pf or 10nF
• 104 is 1 0 0000 or 100,000pf or 100nF

The letter next is the tolerance:

B   +/- 0.10pF
C   +/- 0.25pF
D   +/- 0.5pF
E   +/- 0.5%
F   +/- 1%
G   +/- 2%
H   +/- 3%
J   +/- 5%
K   +/- 10%
M   +/- 20%
N   +/- 30%
P   +100% ,-0%
Z   +80%, -20%


Anything after that is usually manufacturer specific.

• thanks, would you mind giving some inofo over P and Z tolerances? What does it means +80% and -20% at the same time? Jul 10, 2011 at 23:14
• I am not sure, but I would imagine it can be 80% higher than the stated value, or 20% lower - or anywhere in between. I've not seen Z's before. Jul 10, 2011 at 23:16

The "Z" tolerance is most often omitted. If there is no letter after the value then assume it to be "Z". IE: The actual value could be double the shown value or 80% of the shown value - or anything in between. These are suitable as noise decoupling and/or differential coupling applications. Note that they should NOT be used in any kind of timing or oscillator circuits unless the timing or frequency can be suitably adjusted after construction. Also be aware of temperature stability - they usually vary their values considerably with temperature variations.