Capacitor Code

Decode and encode capacitor value codes

Try an example: Decode 104 · Decode 2R2 · Encode 4.7 nF

How it works

Translate common three-character capacitor codes and exactly representable capacitances in picofarads.

For numeric codes, multiply the first two significant digits by ten raised to the third digit; the result is in pF. This tool accepts multipliers 0–6.
In a three-character R code, R represents the decimal point and the resulting number is in pF.
Encoding is exact and does not silently round. Numeric notation is preferred when more than one supported code describes the value.

This covers common three-character capacitance codes only. Markings can be manufacturer-specific or absent, and the code does not identify voltage rating, dielectric, polarity, or tolerance. Check the component datasheet.

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Read capacitor value codes

Decode common three-character capacitor markings into pF, nF and µF, or encode an exactly representable value.

What it is for

Capacitor Code helps translate a common three-character capacitance marking into its nominal value. Choose Decode a code and enter the characters printed on the part or listed in its manufacturer’s part number. The result shows the same capacitance in picofarads (pF), nanofarads (nF) and microfarads (µF).

The tool also works in the other direction. Choose Encode capacitance and enter the nominal value in picofarads. It returns a supported three-character code only when that value can be represented without rounding.

Worked example

For 104, the first two digits are 10 and the third digit means multiply by 10 to the fourth power. The result is 100,000 pF, which is 100 nF or 0.1 µF. Similarly, 472 is 47 × 100, or 4,700 pF (4.7 nF).

Some low-value codes use R as the decimal point. 2R2 represents 2.2 pF and R47 represents 0.47 pF. In encode mode enter 4700 to obtain 472, or enter 2.2 to obtain 2R2. Input is case-insensitive and surrounding spaces are ignored.

How to read the result

For the numeric form, the first digit must be nonzero. The third digit is a base-ten exponent from 0 to 6. For example, 100 means 10 × 10⁰ = 10 pF. With R notation, the tool accepts exactly three characters and reads R as the decimal separator.

The encoder prefers a numeric code if multiple supported spellings express the same value. It does not select a nearest preferred value: 1234 pF, for example, cannot be described by two significant digits and is rejected. Choosing a commercially available value is a separate design decision.

Tips and common mistakes

The calculator covers the indicated common notation, not every capacitor marking system. It intentionally excludes numeric codes ending in 7, 8 or 9, tolerance suffixes, manufacturer-specific abbreviations and longer strings. Read the full part number and use the manufacturer’s own documentation when a code is outside this subset.

A capacitance code alone does not establish working voltage, dielectric material, tolerance, temperature behavior, polarization or safety class. Some tiny ceramic capacitors have no visible value marking at all. Verify the particular part and its datasheet rather than inferring its identity from appearance.

TDK’s ceramic capacitor specification describes the two digits and multiplier in pF. Its automotive specification also illustrates R for a decimal point.

FAQ

Why do I enter picofarads for encoding?

The code’s numerical base unit is pF. Multiply nanofarads by 1,000 or microfarads by 1,000,000 before entering the value.

Does the displayed value include tolerance?

No. It is the nominal capacitance. The actual range and measurement conditions depend on the specific component’s datasheet.

Why was my value rejected?

The supported code has two significant digits or an R decimal marker in three characters. Choose a value that this notation can represent exactly.

Does this code tell me the capacitor voltage rating?

No. Check the full manufacturer part number and datasheet for voltage, temperature and other ratings.

Guide last updated: October 28, 2026

For scripts and AI agents

JSON API: POST https://ohmforgecapacitorcode.usefulweb.site/api/v1/calculate (same calculation as this page)
Interface description: OpenAPI 3.1 · AI guide: llms.txt
MCP server (Streamable HTTP): https://ohmforgecapacitorcode.usefulweb.site/mcp · tool name ohmforge_capacitor_code

Example request

curl -s -X POST https://ohmforgecapacitorcode.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"mode":"decode","code":"104"}'

Feedback · ideas & bug reports welcome