Engineering Reference
Capacitor Code Reference
Engineering reference tables for capacitor marking codes, pF, nF and µF conversion, tolerance suffixes, and common preferred capacitor values.
- Reading Time
- 9 min
- Difficulty
- Reference
- Last Updated
- July 15, 2026
Overview
Capacitor marking codes identify nominal capacitance on small parts where full printed values are impractical. The most common numeric system uses a three-digit pF code: two significant digits followed by a multiplier.
This reference is a lookup-oriented companion to the capacitor code guide. It lists common codes, converted pF, nF, and µF values, tolerance suffixes, and preferred value series from the shared ECParts engineering data layer.
Three-Digit Codes
The first two digits are significant figures. The third digit is the number of zeros to add in picofarads.
Two-Digit Codes
Some small capacitors print direct pF values such as 10, 22, 33, or 47. Manufacturer convention should still be checked.
Suffix Codes
Letters such as J, K, M, and Z commonly identify tolerance, but capacitor family and manufacturer rules can vary.
Common Capacitor Code Table
| Code | Direct Marking | Value | pF | nF | µF | Notes |
|---|---|---|---|---|---|---|
| 100 | 10 | 10 pF | 10 | 0.01 | 0 | A 2-digit marking usually means the value is printed directly in picofarads. |
| 150 | 15 | 15 pF | 15 | 0.015 | 0 | Common small ceramic capacitor value for RF, timing trim, and compensation circuits. |
| 220 | 22 | 22 pF | 22 | 0.022 | 0 | For values below 100 pF, the third digit is often zero, so 220 means 22 pF. |
| 330 | 33 | 33 pF | 33 | 0.033 | 0 | Often used in oscillator load capacitors, filters, and high-frequency networks. |
| 470 | 47 | 47 pF | 47 | 0.047 | 0 | A common small-signal and RF capacitor value. |
| 101 | — | 100 pF | 100 | 0.1 | 0 | The first two digits are significant figures and the third digit is the pF multiplier. |
| 221 | — | 220 pF | 220 | 0.22 | 0 | Common value for filters, compensation, and coupling at high impedance nodes. |
| 331 | — | 330 pF | 330 | 0.33 | 0 | Standard E-series ceramic capacitor marking. |
| 471 | — | 470 pF | 470 | 0.47 | 0 | Frequently found in ceramic capacitors and small filter networks. |
| 102 | — | 1 nF | 1,000 | 1 | 0.001 | The code 102 means 10 x 10^2 pF, equal to 1000 pF or 1 nF. |
| 222 | — | 2.2 nF | 2,200 | 2.2 | 0.002 | A common small ceramic or film capacitor value. |
| 332 | — | 3.3 nF | 3,300 | 3.3 | 0.003 | Used in filters, timing circuits, and coupling networks. |
| 472 | — | 4.7 nF | 4,700 | 4.7 | 0.005 | Standard preferred capacitor value in ceramic and film families. |
| 103 | — | 10 nF | 10,000 | 10 | 0.01 | Often written as 0.01 uF on schematics. |
| 223 | — | 22 nF | 22,000 | 22 | 0.022 | Common in signal coupling, filtering, and timing circuits. |
| 333 | — | 33 nF | 33,000 | 33 | 0.033 | A standard E-series value, especially for ceramic and film capacitors. |
| 473 | — | 47 nF | 47,000 | 47 | 0.047 | Often used as a coupling, filtering, or timing capacitor. |
| 104 | — | 100 nF | 100,000 | 100 | 0.1 | One of the most common decoupling capacitor markings. |
| 224 | — | 220 nF | 220,000 | 220 | 0.22 | Common for filtering and local energy storage. |
| 334 | — | 330 nF | 330,000 | 330 | 0.33 | Used in filtering, bypassing, and timing networks. |
| 474 | — | 470 nF | 470,000 | 470 | 0.47 | Frequently found in ceramic and film capacitor families. |
| 105 | — | 1 uF | 1,000,000 | 1,000 | 1 | The code 105 means 10 x 10^5 pF, equal to 1 uF. |
| 225 | — | 2.2 uF | 2,200,000 | 2,200 | 2.2 | Common ceramic, film, tantalum, and electrolytic nominal value. |
| 475 | — | 4.7 uF | 4,700,000 | 4,700 | 4.7 | Used for local bulk decoupling, timing, filtering, and energy storage. |
| 106 | — | 10 uF | 10,000,000 | 10,000 | 10 | Common bulk, bypass, and power rail capacitor value. |
| 226 | — | 22 uF | 22,000,000 | 22,000 | 22 | Often used in tantalum, ceramic, and electrolytic capacitors. |
| 476 | — | 47 uF | 47,000,000 | 47,000 | 47 | Common bulk capacitance value for power rails and low-frequency filtering. |
| 107 | — | 100 uF | 100,000,000 | 100,000 | 100 | Large capacitance marking often associated with tantalum or electrolytic capacitors. |
Tolerance Suffix Table
| Suffix | Tolerance | Notes |
|---|---|---|
| B | ±0.1 pF | Absolute tolerance used for very small capacitance values. |
| C | ±0.25 pF | Absolute tolerance used for small ceramic capacitors. |
| D | ±0.5 pF | Absolute tolerance used for small capacitance values. |
| F | ±1% | Precision tolerance, often for stable dielectrics. |
| G | ±2% | Precision ceramic or film capacitor tolerance. |
| J | ±5% | Common capacitor tolerance marking. |
| K | ±10% | Very common ceramic capacitor tolerance marking. |
| M | ±20% | Common for ceramic, electrolytic, and tantalum capacitors. |
| Z | -20% / +80% | Wide tolerance marking often associated with high-K ceramics. |
Preferred Capacitor Value Series
| Series | Values per Decade | Typical Tolerance | Typical Applications |
|---|---|---|---|
| E6 | 6 | ±20% | Electrolytic capacitors, bulk capacitance, broad decoupling, low precision timing |
| E12 | 12 | ±10% | General-purpose ceramic, film, electrolytic, and timing capacitor selection |
| E24 | 24 | ±5% | Film capacitors, precision timing, analog filters, tolerance-sensitive selection |
Engineering Notes
- Three-digit codes usually decode to picofarads first.
- Voltage rating is usually not included in the numeric value code.
- Dielectric class strongly affects real capacitance under voltage and temperature.
- Polarized capacitors require separate polarity verification.
- Unknown salvaged capacitors should be measured before reuse.
Standards and Conventions
Capacitor markings follow common EIA and IEC-style commercial conventions, but package size, capacitor family, manufacturer series, and voltage rating can alter the actual marking system. Always verify critical parts against the datasheet.
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FAQ
What unit are three-digit capacitor codes decoded in?
Common three-digit EIA capacitor codes are decoded in picofarads. The first two digits are significant figures and the third digit is the multiplier.
What does 104 mean on a capacitor?
104 means 10 × 10^4 pF, which equals 100,000 pF, 100 nF, or 0.1 µF.
What does 103 mean on a capacitor?
103 means 10 × 10^3 pF, which equals 10,000 pF, 10 nF, or 0.01 µF.
What does 472 mean on a capacitor?
472 means 47 × 10^2 pF, which equals 4,700 pF, 4.7 nF, or 0.0047 µF.
What does K mean after a capacitor code?
K commonly indicates ±10% tolerance, but suffix conventions can vary by capacitor family and manufacturer.
Do capacitor markings always include voltage rating?
No. Numeric capacitor codes usually identify capacitance only. Voltage rating, dielectric type, polarity, temperature rating, and manufacturer series may require datasheet lookup.
Are two-digit capacitor markings always direct pF values?
Many small capacitors use direct two-digit pF markings, but package family and manufacturer convention should still be checked for critical work.
Are capacitor code references enough for production selection?
No. Code references identify nominal value. Production selection also needs voltage rating, tolerance, dielectric, temperature range, ESR, ripple current, package, and reliability review.
Further Reading
- Capacitor Reference category
- Capacitor Guides category
- Capacitor Calculator category
- IEC and EIA marking conventions for capacitors and passive components.