Enter a capacitance value in pF to generate common 3-digit and 4-digit capacitor markings.
Capacitor Code Formula
Many small ceramic and film capacitors use a compact numerical marking instead of printing the complete capacitance value on the component. The common three-digit system uses the first two digits as significant figures and the third digit as a power-of-ten multiplier.
The result of the common three-digit code is normally interpreted in picofarads (pF).
Example: 104
For the code 104, the first two digits are 10 and the multiplier is 10⁴.
Common 3-Digit Capacitor Codes
| Code | Calculation | pF | nF | µF |
|---|---|---|---|---|
| 100 | 10 × 10⁰ | 10 pF | 0.01 nF | 0.00001 µF |
| 101 | 10 × 10¹ | 100 pF | 0.1 nF | 0.0001 µF |
| 102 | 10 × 10² | 1,000 pF | 1 nF | 0.001 µF |
| 103 | 10 × 10³ | 10,000 pF | 10 nF | 0.01 µF |
| 104 | 10 × 10⁴ | 100,000 pF | 100 nF | 0.1 µF |
| 105 | 10 × 10⁵ | 1,000,000 pF | 1,000 nF | 1 µF |
| 221 | 22 × 10¹ | 220 pF | 0.22 nF | 0.00022 µF |
| 222 | 22 × 10² | 2,200 pF | 2.2 nF | 0.0022 µF |
| 223 | 22 × 10³ | 22,000 pF | 22 nF | 0.022 µF |
| 472 | 47 × 10² | 4,700 pF | 4.7 nF | 0.0047 µF |
4-Digit Capacitor Codes
Some capacitors use four numerical digits for greater precision. In the common format, the first three digits are significant and the fourth digit is the multiplier.
Example: 1001
A code of 1001 represents:
Example: 2202
The code 2202 represents:
R-Marked Capacitor Values
Some component marking systems use the letter R as a decimal point. This is particularly useful when a decimal point would otherwise be difficult to see on a small component.
R acts as the decimal marker.
Decimal value using R.
R can represent the decimal point.
R-marked notation is not a universal replacement for the standard three-digit capacitor code. If a marking is unusual or ambiguous, use the manufacturer's datasheet or measure the component with a suitable capacitance meter.
Capacitor Unit Conversion
Capacitor values are commonly expressed in picofarads, nanofarads and microfarads.
| Unit | Equivalent |
|---|---|
| 1 nF | 1,000 pF |
| 1 µF | 1,000 nF |
| 1 µF | 1,000,000 pF |
| 1 pF | 0.001 nF |
| 1 nF | 0.001 µF |
Capacitor Code vs. Other Component Markings
A capacitance code normally identifies only the nominal capacitance. A capacitor can contain additional markings for tolerance, voltage rating, temperature characteristics, dielectric type, polarity or manufacturer-specific information.
Capacitance
The numerical code identifies the nominal capacitance value, such as 100 nF.
Voltage Rating
The voltage rating specifies the maximum rated operating voltage under the manufacturer's specified conditions.
Tolerance
Tolerance specifies how much the actual capacitance can differ from its nominal value.
Worked Capacitor Code Examples
10 × 10¹ pF
10 × 10² pF
10 × 10³ pF
10 × 10⁴ pF
Where Capacitor Code Decoding Is Useful
PCB Repair
Decode markings on small ceramic capacitors when repairing or identifying components on an existing circuit board.
Circuit Analysis
Quickly identify capacitance values when analyzing filters, oscillators, timing circuits and decoupling networks.
Component Identification
Convert compact numerical markings into familiar pF, nF and µF values before selecting replacement components.
Electronics Education
Learn how engineering component markings encode numerical values using significant digits and powers of ten.
Practical Capacitor Identification Tips
- Read the marking carefully. Small ceramic capacitors can have very compact markings that are easy to misread.
- Remember the base unit. The standard three-digit system is normally decoded in picofarads.
- Do not confuse capacitance with voltage. A capacitance code does not normally provide the complete voltage rating of the component.
- Check polarity. Electrolytic and other polarized capacitors require correct orientation in a circuit.
- Check tolerance. Two capacitors with the same nominal capacitance can have different tolerance specifications.
- Use a datasheet for unusual markings. Manufacturer-specific markings may not follow the common numerical system.
- Measure when necessary. A capacitance meter or LCR meter can help verify an unidentified component, although in-circuit measurements can be affected by surrounding components.
Related Electronics Calculators
Capacitor Code Calculator FAQ
How do you read a 3-digit capacitor code?
For the common 3-digit capacitor marking system, the first two digits are significant digits and the third digit is the multiplier. The result is normally expressed in picofarads (pF). For example, 104 means 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 µF.
What does 104 mean on a capacitor?
A capacitor marked 104 is commonly 100 nF, which is also 0.1 µF or 100,000 pF. The code represents 10 × 10⁴ pF.
What does 103 mean on a capacitor?
A 103 capacitor code normally means 10,000 pF, which is 10 nF or 0.01 µF.
What does 102 mean on a capacitor?
A 102 capacitor code normally means 1,000 pF, which is 1 nF or 0.001 µF.
What does 105 mean on a capacitor?
A 105 capacitor code normally means 1,000,000 pF, which is 1 µF.
Are capacitor codes always measured in pF?
The common three-digit ceramic capacitor code system uses picofarads as the base unit. The decoded value can then be converted to nanofarads or microfarads for easier reading.
What does an R mean in a capacitor marking?
An R can be used as a decimal marker in some component markings. For example, 4R7 can represent 4.7 in the relevant capacitance unit. The exact marking convention should be checked against the capacitor manufacturer or datasheet.
Does a capacitor code tell me its voltage rating?
Usually not. A capacitance code primarily identifies capacitance. Voltage rating, tolerance, dielectric type, temperature characteristics and polarity may be indicated separately or require identification from the component marking and datasheet.
What is the difference between a capacitor code and capacitor tolerance code?
The capacitance code identifies the nominal capacitance value. A separate letter or marking may identify tolerance or another electrical characteristic. These markings should not be confused with the capacitance value itself.