Capacitor Code Decoder
Enter a 3-digit capacitor code to decode its capacitance in pF, nF, and µF.
| Capacitor code | Resistance |
|---|---|
| 100 | 10 pF |
| 101 | 100 pF |
| 102 | 1 nF |
| 103 | 10 nF |
| 104 | 100 nF |
| 105 | 1 µF |
| 220 | 22 pF |
| 330 | 33 pF |
| 471 | 470 pF |
| 472 | 4.7 nF |
| 473 | 47 nF |
| 474 | 470 nF |
What is capacitor code decoding?
Small ceramic and film capacitors use a numeric code printed on their body instead of writing the full capacitance value. The code typically consists of three digits: the first two digits are significant figures, and the third digit is the multiplier (power of 10) in picofarads. For example, the code 104 means 10 followed by four zeros = 100,000 pF = 100 nF = 0.1 uF.
This coding system exists because capacitors are often too small to print the full value legibly. Understanding the code lets you quickly identify components when building or repairing circuits. Electrolytic capacitors are large enough to print the value directly (like 100uF/25V), so they do not use this code system.
How the code works
The three-digit code is read in picofarads (pF). The first two digits are the value, and the third is the number of zeros to add. So 473 = 47 followed by 3 zeros = 47,000 pF = 47 nF. Some capacitors add a letter for tolerance: J = 5%, K = 10%, M = 20%. A voltage rating may also appear, like 473K 50V.
How to use this tool
Enter the capacitor code (typically 1-3 digits) and the tool displays the capacitance in picofarads, nanofarads, and microfarads. You can also enter a capacitance value to find the corresponding code. The tool handles all standard codes including single and two-digit codes for very small values.
Common capacitor codes
- 104 = 100 nF (0.1 uF) — The most common decoupling capacitor value.
- 103 = 10 nF — Commonly used for filtering and timing.
- 102 = 1 nF — Used in high-frequency circuits.
- 224 = 220 nF (0.22 uF) — Popular in audio and coupling circuits.
- 105 = 1 uF — Large value for a ceramic capacitor.
Frequently asked questions
What do the letters after the code mean?
Letters indicate tolerance: J = plus/minus 5%, K = plus/minus 10%, M = plus/minus 20%, Z = +80/-20%. The letter may appear after the three-digit code. Some capacitors also include a voltage rating number or letter code.
Why do capacitors use picofarads as the base unit?
The three-digit code system uses picofarads because it allows most common capacitor values to be expressed as whole numbers without decimal points. Values from 1 pF to 99 uF can all be represented with a simple three-digit code, which is ideal for printing on small components.