Decode SMD capacitor markings (104, 473, etc.) to actual capacitance values.
Most ceramic and film capacitors use a 3-digit code. The first two digits are the significant figures, and the third digit is the multiplier (number of zeros to add). The result is in picofarads (pF).
A capacitor is a passive component that stores electric charge, and capacitor identification refers to matching the part marking to its actual usable value. This matters because capacitance value alone is only one part of selection. The same numeric code can still lead to the wrong part if the voltage rating, dielectric behavior, or package family is ignored.
| Code | pF | nF | μF |
|---|---|---|---|
| 100 | 10 pF | 0.01 nF | 0.00001 μF |
| 101 | 100 pF | 0.1 nF | 0.0001 μF |
| 102 | 1,000 pF | 1 nF | 0.001 μF |
| 103 | 10,000 pF | 10 nF | 0.01 μF |
| 104 | 100,000 pF | 100 nF | 0.1 μF |
| 105 | 1,000,000 pF | 1,000 nF | 1 μF |
| 220 | 22 pF | 0.022 nF | 0.000022 μF |
| 221 | 220 pF | 0.22 nF | 0.00022 μF |
| 222 | 2,200 pF | 2.2 nF | 0.0022 μF |
| 223 | 22,000 pF | 22 nF | 0.022 μF |
| 224 | 220,000 pF | 220 nF | 0.22 μF |
| 473 | 47,000 pF | 47 nF | 0.047 μF |
104 means 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 μF. This is one of the most common capacitor values.
Some capacitors use R or n notation. 4R7 = 4.7 pF (R marks decimal point in pF). 2n2 = 2.2 nF (n marks decimal point in nF).
Common tolerance codes: J = ±5%, K = ±10%, M = ±20%. For example, "104K" means 100nF ±10%.
No. Ceramics, film capacitors, and some specialty parts can use different marking styles, and many tiny multilayer ceramic capacitors have no readable mark at all.
Use the marking decoder as a first pass, then confirm dielectric, voltage rating, tolerance, and package details from the BOM or manufacturer datasheet before substitution.