Capacitor Code Guide


When I first started doing electronics, capacitors ("caps") were a real puzzle, and I often just substituted them in a breadboarded circuit until I found one that worked. Finally it occurred to me to do up this chart. Now I have a DMM that reads capacitance, which makes identifying capacitors much simpler.

  • A Farad is the measure of electronic capacitance.
  • Named in honor of scientist Michael Faraday , a pioneer in electronics---
  • The Farad is a HUGE quantity, and most capacitors are only a fraction of a Farad.
  • BEAM projects typically use caps between .001uF and 47uF for timing, signal conditioning, and power filtering; and between 1000uF and 1F for storage in solar engines.

pF = picoFarad, 10-12 farad (that's one trillionth!) 1 uF = 1 000 000 pF

uF = microFarad (the letter u substitutes for the Greek letter micron) 1 F = 1 000 000 uF

mF = microFarad (not milliFarad as you'd expect) 1 F = 1 000 000 000 000 pF

Capacitor values are usually standardized--.10,.22, .33, .47 and so on. However, you might occasionally find an unusual value such as 0.15 or 0.27. You can generally substitute one of these for a single cap in a given circuit. BEAM circuits are often bilateral (two-sided) and balanced, and in these cases try to use the same value on both sides.

The codes below are generally found on ceramic (little round discs) and mylar (chicklet) capacitors, which are not polarized, that is, there are no positive and negative leads.

Usually the first two digits of the code represent part of the value; the third digit corresponds to the number of zeros to be added to the first two digits. This is the value in pf. Some values are usually given in uF, especially those used in BEAM applications, so I have given these as a separate column where appropriate.


VALUE(pF)   CODE            VALUE(pF)	 VALUE(uF)     	CODE
1.5pF                       1,000pF	.001uF 	        102
3.3pF                       1,500pF	.0015uF	        152
10pF                        2,000pF	.002uF 	        202
15pF                        2,200pF	.0022uF	        222
20pF                        4,700pF	.0047uF	        472
30pF                        5,000pF	.005uF 	        502
33pF                        5,600pF	.0056uF	        562
47pF                        6,800pF	.0068uF	        682
56pF                        		.01uF  	        103
68pF                        		.015   
75pF                        		.02    	        203
82pF                        		.022   	        223
91pF                        		.033   	        333
100pF       101             		.047   	        473
120pF       121             		.05    	        503
130pF       131             		.056   	        563
150pF       151             		.068   	        683
180pF       181             		.1     	        104
220pF       221             		.2     	        204
330pF       331             		.22    	        224
470pF       471             		.33    	        334
560pF       561             		.47    	        474
680pF       681             		.56    	        564
750pF       751             		1      	        105
820pF       821             		2      	        205

Tantalum (teardrop shaped) and electrolytic (little cans) capacitors are polarized, so you have to watch what is the positive and negative lead. They are generally higher values and usually have the value printed right on them

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