
How to read capacitor values from their colour or numeric codes
It would be nice if there was more consistency to capacitor markings. If the manufacturer has lots of room (like on big electrolytics) they will usually print everything they can; value, voltage rating, temperature rating, series, even country of manufacture. However, the smaller the part gets, the less information you get until, on the smallest parts there may be nothing at all. On small throughhole ceramics, a twonumberplusexponent
system is often (but not always) used. This, like most marking systems, is based on the picofarad, the lowest common denominator of capacitance. 470 may be 47 (47 x 100) or 470 pF but 471 is almost certainly 470 (47 x 101). 473 will probably be 0.0047. However, 479 will probably mean 4.7 (47 x 10 1). Values below 10 pF may use "R" for a decimal point, 4R7 = 4.7 pF for example. With luck, you might also find the material (C0G, X7R, etc.) and voltage rating. The tolerance may be next to the
value. 




Number 
Multiply By ..
(Additional no. of Zeros) 
0 
None (0) 
1 
10 (1) 
2 
100 (2) 
3 
1,000 (3) 
4 
10,000 (4) 
5 
100,000 (5) 
6 
1,000,000 (6) 

Code 
Tolerance 
C 
±0.25pF 
J 
±5% 
K 
±10% 
M 
±20% 
D 
±0.5pF 
Z 
+80% / 20% 


