First, let's get our nomenclature straight. 1 mF (milli) = 10-3 farad, 1 uF (micro) = 10-6 farad. 1 nF (nano) = 10-9 farad, 1 pF (pico) = 10-12 farad. 1 pF = 10-3 nF =10-6 uF. Nano is rather less common than micro and pico, but it still shows up. 'Femto farad ' (fF) is used for things like RAM chip storage capacitors, but there are no discrete capacitors in that size range.
Well, that's really not true. Microwave capacitors go down to at least 50 fF, but are called 0.05 pF.
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 through-hole ceramics, a two-number-plus-exponent 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. Table 5 shows the EIA tolerance codes for ceramic capacitors. Once again, don't expect to find all possible combinations of values, dielectrics, and tolerances. The tighter tolerances mostly apply to small C0G capacitors and the looser tolerances to larger Class 2-4 ceramics.
For example, if you see .047K, the value is .047 uF 10%.
Acronyms:
RMA: Radio Manufacture's Association. 1924 to 1953.
RETMA: Radio Electronics Television Manufacturers' Association. 1953 to 1957.
EIA: Electronic Industries Alliance. 1957 to 2011. Its various activities were take over by about a half dozen other organizations.
IEC: International Electrotechnical Commission, iec.org, made up from many national standards organizations.
JIS:Japanese Industrial Standards Committee
Standards:
American: EIA RS-19
European: IEC-60384
Japanese: JIS C5101
The three-character code with the letter-number-letter format is used for capacitors with Class 2 and Class 3 dielectrics. C0G is a Class 1 dielectric, so it’s not included (more on this later). X5R and X7R are in Class 2, and Y5V is in Class 3. The first character indicates the lowest temperature that the capacitor can handle. 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. General Capacitance Codebreaker Charts pico-farad (pF) nano-farad (nF) micro-farad (mF,uF or mfd) capacitance code 1000 1 or 1n 0.001 102.
Printable Ceramic Capacitor Code Chart
Nov 21, 2017 - Displayed Capacitor Chart with Tantalum Capacitor Color Codes, Capacitor Code Guide, Mica Capacitor Values etc. Learn deeply about capacitor chart.