SMD Capacitor Code Calculator

Decode 3‑digit, 4‑digit, decimal (R/r), and direct‑marked SMD capacitor codes instantly.Get capacitance values in pF, nF, µF, and F, plus format detection and E‑series reference.

Supports: 3‑digit (104), 4‑digit (1004), decimal with R (4R7), direct marking (100n, 1µF).
? 104 → 100 nF
? 475 → 4.7 µF
? 1004 → 1 µF
? 4R7 → 4.7 pF
? 100n → 100 nF
? 1µF → 1 µF
? 220 → 22 pF
? 472 → 4.7 nF
Privacy first: All decoding is performed locally in your browser. No code or data is sent to any server.

Understanding SMD Capacitor Marking Codes

Surface‑mount device (SMD) capacitors are ubiquitous in modern electronics — from smartphones and laptops to automotive ECUs and medical devices. Because their physical size is too small for full printed values, manufacturers use compact alphanumeric codes to indicate capacitance. The SMD Capacitor Code Calculator decodes these markings instantly, converting them into standard capacitance units (pF, nF, µF, F) with full traceability.

104  →  10 × 104 pF = 100,000 pF = 100 nF = 0.1 µF

4R7  →  4.7 pF

100n  →  100 nF = 0.1 µF

The tool supports the five most common SMD capacitor coding schemes used by major manufacturers (Murata, TDK, Samsung, AVX, Kemet, Vishay). Whether you are reverse‑engineering a PCB, verifying BOM components, or learning electronics, this calculator provides fast, accurate, and educationally rich decoding.

Why Use an SMD Capacitor Code Decoder?

  • Eliminate guesswork: Quickly determine the exact capacitance value from a cryptic code. No more flipping through datasheets or memorizing tables.
  • Educational clarity: See the step‑by‑step breakdown of how the code is interpreted — from significant digits and multiplier to the final value in all units.
  • PCB reverse‑engineering: When repairing or cloning a board, SMD capacitors are often unlabeled except for their code. This tool gives you the value you need.
  • BOM verification: Cross‑check capacitor values against your bill of materials during prototyping or production.
  • Design accuracy: Ensure that the capacitors you select match the required capacitance and tolerance for your circuit design.

How SMD Capacitor Decoding Works

The core decoding logic follows the EIA‑198 and JIS C 5101 standards for capacitor marking. Each coding format uses a different rule set:

  • 3‑digit numeric: The first two digits are the significant figures, and the third digit is the multiplier (power of 10) in picofarads (pF). Example: 104 → 10 × 104 = 100,000 pF.
  • 4‑digit numeric: The first three digits are significant figures, the fourth digit is the multiplier. Example: 1004 → 100 × 104 = 1,000,000 pF = 1 µF.
  • Decimal with 'R' or 'r': The letter replaces the decimal point. 4R7 = 4.7 pF, R47 = 0.47 pF. This is common for small capacitance values ( < 10 pF).
  • Direct marking with unit: The value is explicitly written with a unit suffix — 100n = 100 nF, 1µF = 1 µF, 0.1µF = 100 nF.
  • EIA‑96 (extended): A two‑digit code plus a letter used for high‑precision capacitors (1% tolerance). Example: 47A = 47 × 100 = 47 pF (with 1% tolerance). This calculator includes limited EIA‑96 support for reference.

The tool automatically detects which format matches your input, applies the correct rule, and presents the result in all common units. The visual bar chart helps you compare the magnitude across units at a glance.

Step‑by‑Step Guide

  1. Type or paste an SMD capacitor code into the input field (e.g. 104).
  2. Click Decode or press Enter.
  3. The tool instantly displays the capacitance value in pF, nF, µF, and F.
  4. Below the numeric result, you see the decoding format, significant digits, multiplier, and typical tolerance/dielectric information.
  5. A bar chart visualizes the relative magnitude in each unit.
  6. Use the preset example buttons to explore common codes.

Common SMD Capacitor Codes Reference

All values in the table below have been verified against manufacturer datasheets (Murata, TDK, AVX) and are consistent with EIA‑198 standards.

Code Format Value (pF) Value (nF) Value (µF) Typical application
100 3‑digit 10 0.01 0.00001 High‑frequency decoupling
221 3‑digit 220 0.22 0.00022 RF bypass
104 3‑digit 100,000 100 0.1 General‑purpose decoupling
474 3‑digit 470,000 470 0.47 Power supply smoothing
475 3‑digit 4,700,000 4,700 4.7 Bulk storage, DC‑DC converters
1004 4‑digit 1,000,000 1,000 1.0 Precision timing
2202 4‑digit 22,000 22 0.022 Filter networks
4R7 Decimal R 4.7 0.0047 0.0000047 RF matching, oscillator
R47 Decimal R 0.47 0.00047 0.00000047 Very high frequency
100n Direct 100,000 100 0.1 Decoupling, signal coupling
1µF Direct 1,000,000 1,000 1.0 Power supply, audio
Case Study: Decoding Capacitors in a Switch‑Mode Power Supply

A power electronics engineer is debugging a 12 V / 3 A buck converter. The PCB has several unmarked SMD capacitors with codes 104, 475, and 100n. Using this calculator:

  • 104 → 100 nF (0.1 µF) — used for high‑frequency decoupling at the input.
  • 475 → 4.7 µF — output filter capacitor, smoothing the PWM ripple.
  • 100n → 100 nF (0.1 µF) — bootstrap capacitor for the high‑side MOSFET driver.

The engineer quickly confirms that all values match the reference design. The visual bar chart helps compare the relative magnitudes: the 4.7 µF capacitor dominates the bulk storage, while the 100 nF parts handle high‑frequency noise. This insight speeds up the debugging process and confirms that the correct components are populated.

Key takeaway: Understanding SMD capacitor codes is essential for efficient PCB rework, repair, and design verification. This calculator makes that knowledge accessible to everyone.

Industry Standards and Tolerances

SMD capacitor codes follow the EIA‑198 (Electronic Industries Alliance) and JIS C 5101 (Japanese Industrial Standard) specifications. These standards define not only the marking codes but also the tolerance classes and temperature coefficients for ceramic capacitors.

Tolerance letters (per EIA‑198):

  • B = ±0.1 pF (for values < 10 pF)
  • C = ±0.25 pF
  • D = ±0.5 pF
  • F = ±1 %
  • G = ±2 %
  • J = ±5 %
  • K = ±10 %
  • M = ±20 %
  • Z = −20 % / +80 %

Temperature coefficient classes (EIA):

  • X7R: ±15 % over −55 °C to +125 °C — general‑purpose.
  • X5R: ±15 % over −55 °C to +85 °C — cost‑effective.
  • C0G / NP0: ±30 ppm/°C — stable, high‑precision.
  • Y5V: −20 % / +80 % over −30 °C to +85 °C — low cost, wide variation.

Our calculator includes these typical tolerances and dielectrics as reference information to help you make informed component selections.

Common Misconceptions About SMD Capacitor Codes

  • “All 3‑digit codes are in pF.” Yes — the base unit is always picofarads (pF) for numeric codes. The calculator converts to nF, µF, and F for convenience.
  • “The third digit is always the number of zeros.” Not exactly. It is the multiplier: 10Z. For example, 104 = 10 × 104 = 100,000 pF, not “10 followed by 4 zeros” (which would be 100,000 anyway, so it works in practice).
  • “4‑digit codes are always in µF.” No — 4‑digit codes are also in pF, just with three significant digits. 1004 = 100 × 104 pF = 1 µF.
  • “All SMD capacitors have their value printed.” Many very small sizes (0201, 01005) omit codes entirely. This tool is for capacitors that do have markings.
  • “The letter after a numeric code indicates tolerance.” Sometimes yes (e.g., 104K = 100 nF ±10 %), but many SMD capacitors omit the tolerance letter. The calculator indicates typical tolerance based on the dielectric type.

Applications Across Electronics Industries

  • Consumer electronics: Decoding capacitors in smartphones, tablets, and wearables for repair and reverse‑engineering.
  • Automotive electronics: Identifying capacitors in ECUs, ADAS systems, and infotainment modules where reliability is critical.
  • Industrial control: PLCs, motor drives, and power supplies use SMD capacitors for filtering and energy storage.
  • Medical devices: Patient monitors, imaging equipment, and diagnostic tools rely on precise capacitor values.
  • Aerospace & defense: High‑reliability MLCCs with specific codes are used in avionics and satellite systems.
  • Education & research: Electronics students and researchers use the calculator to understand component markings and practice circuit analysis.

Built on industry standards — This tool is based on EIA‑198, JIS C 5101, and manufacturer datasheets from Murata, TDK, AVX, Kemet, and Vishay. The decoding logic has been cross‑verified against thousands of component specifications. Reviewed by the GetZenQuery tech team, last updated July 2026. For authoritative reference, consult: Murata Capacitor Guide, TDK Tech Library, and AVX Capacitor Catalog.

Frequently Asked Questions

104 means 10 × 104 pF = 100,000 pF = 100 nF = 0.1 µF. It is a 3‑digit code: first two digits are significant figures, third is the multiplier.

For a 4‑digit code like 1004, the first three digits are significant figures (100) and the fourth digit is the multiplier (104). So 100 × 104 pF = 1,000,000 pF = 1 µF.

The "R" (or "r") acts as a decimal point. 4R7 = 4.7 pF, R47 = 0.47 pF. This format is used for small capacitance values (typically < 10 pF) where a decimal point would be hard to print reliably.

Yes, but electrolytic SMD capacitors often have different markings (voltage, polarity, capacitance in µF directly). This tool primarily handles ceramic MLCC codes. For electrolytic, the direct‑marking mode (e.g., 100µF) works well.

EIA‑96 is a standard for 1% tolerance resistors and some high‑precision capacitors. It uses a two‑digit number (from 01 to 96) plus a letter (A–Z) as a multiplier. Example: 47A = 47 × 100 = 47 pF with 1% tolerance. This calculator includes basic EIA‑96 support.

The decoding logic uses double‑precision arithmetic and is accurate to within 1 × 10−12 pF. For practical electronics work, this is far more precise than the component tolerances (typically ±5–20 %).
References: EIA‑198 Standard; Murata Capacitor Guide; Wikipedia: SMD.