Capacitor Code Converter

Capacitor codes use a 3-digit system similar to resistor color codes.

Reading the code:

• First two digits = significant figures
• Third digit = number of zeros (multiplier in picofarads)
• Example: 104 = 10 + 0000 = 100,000 pF = 100 nF = 0.1 uF

Common capacitor codes:

Unit conversions:

• 1 F = 1,000,000 uF = 1,000,000,000 nF = 1,000,000,000,000 pF
• 1 uF = 1,000 nF = 1,000,000 pF
• 1 nF = 1,000 pF

The 3-digit code exists because small capacitors are too tiny to print a full value like “0.1 µF” on. The system works just like scientific notation: the first two digits are the value, the third is how many zeros to add, giving the result in picofarads. So 104 is 10 followed by four zeros, 100,000 pF, which is 100 nF or 0.1 µF, one of the most common decoupling capacitors in all of electronics.

Two things trip up beginners. First, the result is always in picofarads, so you usually convert up to nF or µF to match a schematic. Second, many capacitors add a tolerance letter after the code: J means ±5%, K means ±10%, M means ±20%. A capacitor marked “104K” is a 0.1 µF part good to within 10%. The code gives the nominal value; the letter tells you how close the real part is likely to land, which matters in timing and filter circuits where precision counts.