How to Read a Capacitor Code

Most small ceramic capacitors print a 3-digit EIA code instead of the full value. The first two digits are significant figures, and the third digit tells you how many zeros to add — in picofarads (pF). For example, 104 means 10 followed by 4 zeros: 100,000pF, which is 100nF or 0.1µF.

Some capacitors instead use a letter as a decimal point and unit marker, like 4n7 (4.7nF) or 2p2 (2.2pF). This decoder handles both formats, plus plain values like 2.2uF.

Common Capacitor Codes

CodeValue
101100pF
221220pF
471470pF
1021nF (1000pF)
10310nF
104100nF (0.1µF)
1051µF
224220nF (0.22µF)
474470nF (0.47µF)

Want to know what a capacitor actually does in a circuit? Read What Is a Capacitor?, or check the Resistor Color Code Calculator for the equivalent on resistors.