Capacitor codes and conversions

As small general purpose capacitors values range from a few pF to less than 1 µF the convention arose that whole numbers designate values in picofarads while decimal fractions designates values in microfarads. Any capacitor with a value of 1 µF or above is large enough to be marked with its actual value. A newer way to mark values is with three numbers on the body of the capacitor. The value is in picofarads, the the third digit is a multiplier. So for example 151 indicates a capacitance of 150 pF.

Often p, n and u are substituted for the decimal point. For example 8p2 for 8.2pF, n51 for 0.51nF or 4u7 for 4.7µF.