The farad (F) is the unit of capacitance, a measure of a capacitor’s ability to store electric charge per unit voltage. One farad is defined as the capacitance of a capacitor when one coulomb of electric charge causes a potential difference of one volt across its terminals. The farad is a relatively large unit, and capacitance values for most capacitors are often expressed in microfarads (μF), nanofarads (nF), or picofarads (pF).