# Capacitor Code

> Decode and encode capacitor value codes Translate common three-character capacitor codes and exactly representable capacitances in picofarads.

Part of usefulweb.app (https://usefulweb.app/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://ohmforgecapacitorcode.usefulweb.app/ (interactive tool at https://ohmforgecapacitorcode.usefulweb.app/tool)
- JSON API: POST https://ohmforgecapacitorcode.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://ohmforgecapacitorcode.usefulweb.app/api/v1/tool)
- OpenAPI: https://ohmforgecapacitorcode.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://ohmforgecapacitorcode.usefulweb.app/mcp - tool `ohmforge_capacitor_code`

## Inputs
- mode (select): Calculate
- code (text): Three-character code (decode) - For example 104 or 2R2. R is the decimal point.
- picofarads (number): Capacitance in pF (encode)

## Method
- 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.

## Limits
- 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.