Capacitor marked mFd or MFD but all I can find are µF caps?


There are a lot of capacitors that use the marking MFD or mFd after the capacitance value.

This marking most often on capacitors is actually the same as µF. The µF stands for microFarad.

It was common practice on older capacitors to be marked as MFD or mFd either for machinery difficulty to produce the µ symbol print on the casing or for other manufacturer specific reasons.

Here is an example of a capacitor that is still active - The product is listed as 330 uF per our product page and also per the manufacturer datasheet yet the label may show MFD after the value.

There is some confusion to this as mFd could be interpreted as milliFarad rather than microFarad but milliFarad is not a very common range for Aluminum electrolytic, Film , or Ceramic capacitors and the values they may be be listed as.

Common Resistor and Capacitor Values
How to measure the capacitance of Supercapacitors/EDLCs

Millifarad (mF) values though are pretty common in supercapacitors such as these.