The microfarad (symbolized µF) is a unit of capacitance, equivalent to 0.000001 (10 to the -6th power) farad. The microfarad is a moderate unit of capacitance. In utility alternating-current (AC) and audio-frequency (AF) circuits, capacitors with values on the order of 1 µF or more are common. At radio frequencies (RF), a smaller unit, the picofarad (pF), is often used. This unit is equal to .000000000001 (10^-12) µF.
In RF scenarios, capacitances range from about 1 pF to 1,000 pF in tuned circuits, and from about 0.001 µF to 0.1 µF for blocking and bypassing. At audio frequencies (AF), capacitances range from about 0.1 µF to 100 µF. In power-supply filters, capacitances can be as high as 10,000 µF.