Color Code Calculator

Resistor · Capacitor · Inductor — live band drawing, reverse mode & E-series snapping

Resistance

Unit

Tolerance

Bands

3-digit EIA Code e.g. 104 = 100 nF, 223 = 22 nF, 470 = 47 pF. Optional tolerance letter (104K).

Colour-band ceramic capacitor decoder (older style)

Common voltage rating quick-reference

Inductor colour bands read like resistors but the value is in microhenries (µH). Silver/gold in the first band position indicate a decimal point on some parts — verify with a meter for critical work.

Colour codes follow IEC 60062. Real components can be ambiguous (band order, worn colours) — always confirm critical values with a multimeter.

Color Code Calculator: Resistor, Capacitor and Inductor Value Decoder

Reading tiny color bands on a resistor or decoding a 3-digit number printed on a capacitor, is a common source of mistakes. This tool solves both in one place – decode 4, 5 or 6-band resistor colors into a value with a live redrawing diagram or go the other way and find the bands for a known value. it also decodes capacitor EIA codes (like “104” for 100nF) and inductor color bands.

How to Use

For Resistors:

Select Resistor mode, then Colours → Value (to decode) or Value → Colours (to find bands for a known value).
Pick the band count – 4, 5, or 6.
In decode mode, select each band’s color and watch the value update live on the diagram.
In reverse mode, enter resistance, unit and tolerance, then click Find Band Colours.

For Capacitors:

Select Capacitor mode, enter the printed 3-digit EIA code (e.g., “104”), optionally with a tolerance letter.
Click Decode Capacitor to see the value in pF/nF/µF.

For Inductors:

Select Inductor mode, choose 3-band or 4-band and select each band’s color for the value in µH.

Key Features

Resistor decoding for 4, 5, and 6-band types with a live, redrawing SVG diagram
Reverse mode – enter a resistance and get the exact bands to look for
Automatic nearest E-series (E12/E24/E96) match, so you know if your value is a standard stock size
Capacitor EIA code decoder (“104” → 100nF) with tolerance letter support
Older-style color-band ceramic capacitor decoder included
Inductor color band decoder (3-band and 4-band), values in microhenries (µH)
Common capacitor voltage rating quick-reference
Export as PDF or copy the result

Formula / Logic Used

Resistor Value (Colours → Value) $Resistance = (D_1 D_2 [D_3]) \times Multiplier \ \Omega, \ \pm Tolerance\%$

Where $D_1, D_2$ (and $D_3$ for 5/6-band) are the significant digit bands, $Multiplier$ is a power of 10 from the multiplier band and $Tolerance$ comes from the tolerance band color.

Nearest E-Series Match

The tool compares your calculated resistance against the standard E12, E24 and E96 series (defined by IEC 60063) and reports the closest standard value – useful to check if a component is a common stock size or an unusual one.

Capacitor EIA Code $Value\ (pF) = (D_1 D_2) \times 10^{D_3}$

Example: “104” → 10 × 10⁴ = 100,000 pF = 100 nF.

Who Should Use This Tool

Diploma and B.Tech ECE/Electrical students identifying component values in lab work. Also useful for hobbyists sorting through mixed component bins without a multimeter handy.

Frequently Asked Questions (FAQs)

1. How do I read a 5-band resistor color code?

The first three bands are significant digits, the fourth is the multiplier and the fifth is tolerance. Select each band’s color here to see the resistance value with its tolerance range instantly.

2. What does the EIA code “104” mean on a capacitor?

It means 10 × 10⁴ picofarads, equal to 100,000 pF or 100 nF. This tool decodes any 2-3 digit EIA code (with optional tolerance letter) into pF, nF, and µF directly.

3. What’s the difference between a 4-band and 5-band resistor?

A 4-band has 2 significant digits, a multiplier and a tolerance band. A 5-band adds a third significant digit for finer precision, common in tighter-tolerance parts. Both are supported here in forward and reverse modes.

4. What is E-series and why does it matter for resistor values?

E-series (E12, E24, E96) are standardized “preferred values” that manufacturers actually stock. This tool checks your calculated value against these series so you know if it’s a standard part or an unusual custom one.

5. How do inductor color codes differ from resistor color codes?

Inductor bands are read the same way (digits + multiplier + tolerance), but the value is in microhenries (µH) instead of ohms. This tool includes a separate inductor mode with both 3-band and 4-band decoding.

Related Tools

Op-Amp Gain/Filter Designer – use decoded resistor and capacitor values directly in a filter design
PCB Trace Width Calculator – plan your board layout around these components
Electrical Symbol Finder – find the correct schematic symbol for the decoded component

Resistor Color Code Calculator: 4/5/6-Band + Capacitor & Inductor