Bench tool

Capacitor Toolkit

Decode a printed capacitor code, read tantalum or "tropical fish" color bands, or work backward from a target value to the code you need.

Install on your phone This tool is also available as a mobile app — full offline access, right from your home screen, no browser tab required. Get the Capacitor Toolkit app

Code Reader

Type the marking printed on the capacitor body. Handles 3-digit and 4-digit EIA codes, "R" pico notation, n/u unit notation, and an optional leading voltage code plus trailing tolerance letter.

Printed marking

100 nF

100,000 pF · 0.1 µF

Tolerance: ±10%

Couldn't parse that marking — check the digits/letters and try again.

Format: 3-digit EIA code

Quick reference — 104 = 10×10⁴ pF = 100 nF · 474K = 470 nF ±10% · 3R9 = 3.9 pF · 4N7 = 4.7 nF · 6U8 = 6.8 µF · 2A474J = 470 nF, ±5%, 100 V

Color Code Decoder

Color-banded capacitors are older stock — dipped tantalum beads and Mullard-style "tropical fish" film caps. Pick the type and click through the bands to match what's in your hand.

1.0 µF

1,000,000 pF · 1,000 nF

Reverse Lookup

Enter the value you need and get back the EIA numeric code to look for — useful when you're cross-referencing a parts drawer or a schematic BOM.

Target value

Code length

Tolerance

Voltage code (optional)

This value can't be represented exactly with that code length — showing the closest match.

MARKING TO LOOK FOR

104K

= 100 nF ±10%

Codes give the nearest representable value for the digit count chosen — a 3-digit code carries two significant figures, a 4-digit code carries three. If the target isn't landing exactly, try the other code length.