Reference chart

Capacitor code chart

Print it: Capacitor codes cheat sheet (PDF: A4 · US Letter)

Small capacitors are too tiny to print "100 nF" on, so they carry a short code instead: 104, 473J or 2A. This chart turns the code into a value in pF, nF and µF, a tolerance and a voltage rating.

Reading a 3-digit code

The code is in picofarads (pF). The first two digits are the value and the third is how many zeros follow:

104 = 10 and 4 zeros = 100,000 pF = 100 nF

473 = 47 and 3 zeros = 47,000 pF = 47 nF
222 = 22 and 2 zeros = 2,200 pF = 2.2 nF
101 = 10 and 1 zero = 100 pF

A third digit of 9 means divide by ten: 109 is 1.0 pF. Values under 100 pF are often printed as they are, so "22" or "47" on a tiny ceramic means 22 pF or 47 pF.

Common codes

Code	pF	nF	µF
100	10 pF	0.01 nF	0.00001 µF
220	22 pF	0.022 nF	0.000022 µF
101	100 pF	0.1 nF	0.0001 µF
221	220 pF	0.22 nF	0.00022 µF
471	470 pF	0.47 nF	0.00047 µF
102	1,000 pF	1 nF	0.001 µF
222	2,200 pF	2.2 nF	0.0022 µF
472	4,700 pF	4.7 nF	0.0047 µF
103	10,000 pF	10 nF	0.01 µF
223	22,000 pF	22 nF	0.022 µF
473	47,000 pF	47 nF	0.047 µF
104	100,000 pF	100 nF	0.1 µF
224	220,000 pF	220 nF	0.22 µF
474	470,000 pF	470 nF	0.47 µF
105	1,000,000 pF	1,000 nF	1 µF
225	2,200,000 pF	2,200 nF	2.2 µF
475	4,700,000 pF	4,700 nF	4.7 µF
106	10,000,000 pF	10,000 nF	10 µF

Some makers print the value with the prefix as the decimal point instead: 4n7 is 4.7 nF, 2p2 is 2.2 pF and µ47 (or u47) is 0.47 µF. On older capacitors a plain decimal like .1 or 0.047 is in µF.

Tolerance letters

A letter straight after the code gives the tolerance: how far the real value may be from the printed one.

Letter	Tolerance	Letter	Tolerance
B	±0.1 pF	G	±2%
C	±0.25 pF	J	±5%
D	±0.5 pF	K	±10%
F	±1%	M	±20%
		Z	+80% / −20%

B, C and D are for capacitors under about 10 pF, where a percentage would be too small to mean much. Z is common on cheap ceramic discs: the real value is usually above the printed one.

Voltage codes

Big capacitors print their voltage rating in plain numbers, like 25 V. Film capacitors and some ceramics use a two-character code instead:

Code	Voltage	Code	Voltage
0J	6.3 V	1J	63 V
1A	10 V	2A	100 V
1C	16 V	2D	200 V
1E	25 V	2E	250 V
1V	35 V	2G	400 V
1H	50 V	2J	630 V

So a film capacitor marked 2A104J is 100 nF, ±5%, rated for 100 V. Tiny surface-mount ceramics usually have no marking at all, so keep them in their labelled tape.

Reading a capacitor, step by step

Electrolytic (a can with a stripe): the value and voltage are printed in full, like 470 µF 25 V. The stripe marks the − leg.
Ceramic or film with three digits: read the value in pF, then move to nF or µF.
A letter after the digits: that's the tolerance.
A digit-and-letter pair like 1H or 2A elsewhere on the body: that's the voltage.

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The ideas behind it

Questions people ask

What does 104 mean on a capacitor?

104 means 10 followed by four zeros, in picofarads: 100,000 pF. That's 100 nF, or 0.1 µF. It's the most common capacitor there is, the one that sits by every chip's power pin.

Is 104 the same as 0.1 µF and 100 nF?

Yes. 100,000 pF, 100 nF and 0.1 µF are the same value written with different prefixes. Each step from pF to nF to µF divides by 1000.

What do J, K and M mean after a capacitor code?

They give the tolerance: J is ±5%, K is ±10% and M is ±20%. So 473K is 47 nF, and the real part can be anywhere from about 42 nF to 52 nF.

What does 2A or 1H mean on a capacitor?

It's a voltage code. 1H means 50 V and 2A means 100 V. The digit sets the decade and the letter the value within it, so check the voltage table rather than guessing.