Capacitor Code Lookup

The three digits on the case are picofarads in disguise: two digits and a count of zeros. Type them in.

Code on the case

code

How the code works

First digit, second digit, then the number of zeros, all in picofarads. So 104 is 10 followed by four zeros: 100,000 pF, which is 100 nF, which is 0.1 µF. All three spellings mean the same capacitor, which is exactly why this converter shows all three at once.

The other markings

A letter after the digits is tolerance: J is 5%, K is 10%, M is 20%. An R inside the digits is a decimal point (4R7 is 4.7 pF). One or two lone digits are just the value in pF. Electrolytics skip codes entirely and print the real value and voltage, because there's room on the can.

The conversion table

Code	Picofarads	Nanofarads	Microfarads	Seen in
100	10 pF	0.01 nF	0.00001 µF	crystal load caps
101	100 pF	0.1 nF	0.0001 µF	RF, snubbers
102	1,000 pF	1 nF	0.001 µF	filters
103	10,000 pF	10 nF	0.01 µF	debounce, 555 CTRL
104	100,000 pF	100 nF	0.1 µF	decoupling, everywhere
105	1,000,000 pF	1,000 nF	1 µF	coupling, timing
106	-	-	10 µF	supply smoothing
107	-	-	100 µF	bulk electrolytics

Multiply by 1,000 to move a column left, divide by 1,000 to move right. The value everyone reaches for, the 104 decoupling capacitor, is 100 nF, and datasheets will spell it all three ways in the same document just to keep you sharp.