Capacitor Color Code: Reading & Identification Guide

Pick up a handful of old through-hole capacitors from a spares bin and you’ll quickly run into the capacitor color code system — a series of coloured bands that encodes capacitance value, tolerance, and working voltage into a compact visual label. Pick up a modern PCB and you’ll mostly find ceramic disc and film capacitors marked with short numeric codes, or SMD MLCCs with no marking at all. Both worlds require different decoding skills, and both come up regularly in repair work, prototyping, and vintage electronics restoration.

This guide covers the complete capacitor identification system: the colour band system used on older through-hole types, the 3-digit numeric code used on ceramic disc and film capacitors, tolerance letter codes, voltage markings, and how to handle modern SMD parts where the code is often absent entirely. Worked examples throughout, with full reference tables for bench use.

## Why Capacitors Use Code Systems Instead of Printing Full Values

The short answer is space. A ceramic disc capacitor with a body diameter of 4–5mm simply doesn’t have room to print “0.047µF ±10% 50V” in a legible font. Neither does a 0402 MLCC measuring 1.0mm × 0.5mm. So manufacturers use shorthand encoding systems that pack the key specifications into as few characters as possible.

For larger through-hole electrolytic capacitors — where the can body is big enough — full values are printed directly: “100µF 25V” stamped on the side is unambiguous. The colour band and numeric code systems exist for smaller parts where direct marking isn’t practical.

The colour code system was standardised by the IEC in 1952 and extended to capacitors by 1968, following the same spectral colour-to-digit mapping already established for resistors. It’s now largely obsolete in new production but remains essential knowledge for anyone working with equipment from the 1950s through the 1990s. The numeric code system (the 3-digit EIA code) has replaced it on most modern through-hole ceramics and films and remains in widespread use today.

## The Capacitor Colour Code System: Complete Reference

The colour code for capacitors works almost identically to the resistor colour code. Each colour corresponds to a digit (0 through 9), and bands appear in a defined order: first significant digit, second significant digit, multiplier, tolerance, and (on some types) voltage rating. All values are in picofarads (pF) as the base unit.

### The Colour-to-Digit Mapping

This table is the foundation of every colour band capacitor reading. It is the same mapping used for resistors, so if you already know the resistor colour code, you know this.

Capacitor Colour Code Reference Table:

Colour	Digit	Multiplier (pF)	Tolerance (>10pF)	Tolerance (≤10pF)
Black	0	×1	±20%	±2.0pF
Brown	1	×10	±1%	±0.1pF
Red	2	×100	±2%	±0.2pF
Orange	3	×1,000	—	—
Yellow	4	×10,000	—	—
Green	5	×100,000	±5%	±0.5pF
Blue	6	×1,000,000	—	—
Violet	7	—	—	—
Grey	8	×0.01	—	±0.25pF
White	9	×0.1	±10%	±1.0pF
Gold	—	×0.1	±5%	±0.5pF
Silver	—	×0.01	±10%	±1.0pF

Reading direction: on most capacitors with colour bands, you read from the end where the bands are closest together, moving toward the more isolated bands. On tubular capacitors, read from the top down (the end nearest to a lead is typically the starting point).

### Voltage Rating by Colour Band

The voltage rating, when encoded as a colour band (usually the 5th band on polyester/polystyrene types), uses a separate table that varies by capacitor type. The most common encoding for Type L (polyester/polystyrene) and Type K (mica) capacitors is:

Voltage Rating Colour Codes:

Colour Band	Voltage Rating
Red	250V
Yellow	400V
Blue	630V
White	not defined (check datasheet)
No band / body colour	Voltage determined by capacitor type

For Type J (dipped tantalum), the voltage colour bands use a different table specific to that type. When in doubt, check the datasheet for the specific capacitor series.

### Capacitor Types That Use Colour Bands

Not all through-hole capacitors use colour bands. The system was predominantly applied to four types, each with slightly different band positioning and interpretation:

Type J — Dipped Tantalum: Typically 3 colour bands (value only, no tolerance or voltage band). Values in pF.

Type K — Mica: 6-dot system or band system. The first dot/band is white (EIA code) or black (military code). Reads capacitance in pF from the next three bands, then tolerance on the 5th, then temperature/leakage class on the 6th.

Type L — Polyester/Polystyrene (including the famous “Mullard tropical fish” capacitors): 5 colour bands reading from top to bottom — two significant digits, multiplier, tolerance, and working voltage.

Type M — Electrolytic, 4-band: Four bands encoding two digits, multiplier, and tolerance.

Type N — Electrolytic, 3-band: Three bands encoding two digits and multiplier only.

## Working Through Colour Band Examples

### Example 1: Five-Band Polyester Capacitor (Type L)

Bands (top to bottom): Yellow — Violet — Orange — White — Red

• Yellow = 4 (1st digit)
• Violet = 7 (2nd digit)
• Orange = ×1,000 (multiplier)
• White = ±10% (tolerance, above 10pF)
• Red = 250V (voltage)

Capacitance = 47 × 1,000 = 47,000 pF = 47nF = 0.047µF, ±10% tolerance, 250V working voltage.

### Example 2: Three-Band Dipped Tantalum (Type J)

Bands: Brown — Black — Orange

• Brown = 1 (1st digit)
• Black = 0 (2nd digit)
• Orange = ×1,000 (multiplier)

Capacitance = 10 × 1,000 = 10,000 pF = 10nF = 0.01µF. No tolerance or voltage band — check the component datasheet for these parameters.

### Example 3: Four-Band Electrolytic (Type M)

Bands: Brown — Green — Red — Black

• Brown = 1 (1st digit)
• Green = 5 (2nd digit)
• Red = ×100 (multiplier)
• Black = ±20% (tolerance)

Capacitance = 15 × 100 = 1,500 pF = 1.5nF, ±20% tolerance.

Capacitor Colour Band Worked Examples Summary:

Band Sequence	Type	Result
Yellow, Violet, Orange, White, Red	Type L (polyester)	47nF, ±10%, 250V
Brown, Black, Orange	Type J (tantalum)	10nF (no tolerance/voltage encoded)
Brown, Green, Red, Black	Type M (electrolytic)	1.5nF, ±20%
Orange, White, Yellow, Gold	Type K (mica, 4 dots)	390nF, ±5%
Brown, Black, Orange, Gold, Red	Type L (polyester)	10nF, ±5%, 250V

## The 3-Digit Numeric Code: What You’ll Find on Most Modern Capacitors

The colour band system is largely obsolete in new production. The vast majority of ceramic disc capacitors, small film capacitors, and through-hole types manufactured from the 1980s onward carry a 3-digit numeric code instead of colour bands. This is the system you’ll encounter every day on a modern repair bench or in a new design.

### How to Read the 3-Digit Capacitor Code

The 3-digit code works exactly like the colour band multiplier system, using digits instead of colours:

• First two digits: the two significant figures of the capacitance value
• Third digit: the multiplier, representing 10 raised to that power — that is, the number of zeros to append
• Base unit: always picofarads (pF)

So the code reads: value = (1st digit)(2nd digit) × 10^(3rd digit) pF

The single most important rule that trips up everyone new to this system: the third digit is a multiplier exponent, not a third significant digit. The code “104” does not mean 104 pF — it means 10 × 10⁴ = 100,000 pF = 100nF = 0.1µF.

3-Digit Code Multiplier Reference:

3rd Digit	Multiply By	Add This Many Zeros
0	×1	0 zeros — value is XX pF
1	×10	1 zero
2	×100	2 zeros
3	×1,000	3 zeros
4	×10,000	4 zeros
5	×100,000	5 zeros
6	×1,000,000	6 zeros
8	×0.01	divide by 100
9	×0.1	divide by 10

Note that the digits 7 is rarely used; digits 8 and 9 produce sub-unity multipliers for small pF values.

### Common 3-Digit Codes and Their Values

This table covers the codes you’ll see most frequently on a typical PCB, translated into the three unit systems engineers use day-to-day:

Common Ceramic Capacitor 3-Digit Codes:

Printed Code	Picofarads (pF)	Nanofarads (nF)	Microfarads (µF)	Typical Application
100	10 pF	0.01 nF	—	RF circuits, oscillators
101	100 pF	0.1 nF	—	RF bypass, small coupling
102	1,000 pF	1 nF	0.001 µF	High-frequency filter
103	10,000 pF	10 nF	0.01 µF	Signal coupling, bypass
104	100,000 pF	100 nF	0.1 µF	Most common bypass cap
105	1,000,000 pF	1,000 nF	1 µF	Power supply decoupling
220	22 pF	0.022 nF	—	Crystal load cap
470	47 pF	0.047 nF	—	RF tuning, antenna matching
471	470 pF	0.47 nF	—	IF filter, small coupling
472	4,700 pF	4.7 nF	0.0047 µF	Snubber networks
473	47,000 pF	47 nF	0.047 µF	Filter, coupling
474	470,000 pF	470 nF	0.47 µF	Power supply filter

### The “R” Decimal Point Convention

For capacitance values below 10 pF, the 3-digit system would require sub-unity multipliers (digits 8 or 9), which can be ambiguous. Instead, many manufacturers use the letter “R” as a decimal point within the code:

• 4R7 = 4.7 pF
• 3R3 = 3.3 pF
• 1R0 = 1.0 pF
• 5R6 = 5.6 pF

This is borrowed from the same convention used in resistor markings (where “4R7” means 4.7Ω) and eliminates the ambiguity of a decimal point that could be missed when the printing is small or worn.

## Tolerance Letter Codes

Most ceramic and film capacitors printed with a 3-digit code also carry a single letter suffix indicating tolerance. This letter is printed immediately after the numeric code — for example, 104K means 100nF ±10%.

Capacitor Tolerance Letter Code Reference:

Letter	Tolerance	Notes
B	±0.1 pF	Precision types only; for values ≤10pF
C	±0.25 pF	Precision types only
D	±0.5 pF	Precision / C0G types
F	±1%	Precision film, C0G ceramic
G	±2%	Film capacitors
J	±5%	Common on film, C0G ceramic
K	±10%	Standard X7R, film types
M	±20%	Standard electrolytic, Z5U ceramic
Z	+80% / −20%	General-purpose electrolytics

A real-world example: a ceramic disc marked 473J decodes as 47 × 10³ = 47,000 pF = 47nF, ±5% tolerance. A polyester film marked 104K is 100nF ±10%.

## Voltage Markings on Capacitors

Voltage rating tells you the maximum DC voltage the capacitor can withstand continuously. On larger electrolytics and tantalums, it’s printed directly: “16V”, “50V”, “100V”. On smaller ceramics and films, it may appear as a letter code — the EIA voltage code system — or simply as a number followed by “V” or “VDC”.

EIA Voltage Letter Codes (used on some SMD and small through-hole types):

Code	Voltage Rating
e	2.5V
G	4V
J	6.3V
A	10V
C	16V
D	20V
E	25V
V	35V
H	50V
Y	63V
P	100V
2A	100V
2B	125V
2C	160V
2D	200V
2E	250V

If no voltage marking is visible, treat the capacitor as low-voltage rated (assume 16–25V maximum) unless the circuit documentation or datasheet confirms otherwise.

## Identifying SMD Capacitors: The Special Challenge

Modern PCBs are dominated by SMD MLCCs (multilayer ceramic capacitors), and these present a unique identification problem: most of them carry no visible markings at all.

### Why Most SMD MLCCs Are Unmarked

The manufacturing process explains this directly. MLCC chips are fired at over 1,000°C to sinter the ceramic layers and electrodes into a monolithic block. Any marking applied before firing would be destroyed. Applying a post-fire marking is technically possible but adds cost and process steps that are impractical for components produced in the billions. The result: the majority of 0402, 0603, and 0805 MLCCs you encounter on a board have blank, beige-coloured surfaces.

For unmarked SMD ceramics, the component value is encoded in the supply reel label and the PCB’s Bill of Materials. There is no way to visually determine the value — you need the BOM, the assembly data, or a measurement with an LCR meter or smart tweezers.

### SMD Capacitors That Do Carry Markings

Two SMD types that regularly carry markings are SMD tantalum capacitors and larger SMD aluminium electrolytics (V-chips).

SMD tantalum capacitors typically have enough package real estate to print capacitance, voltage, and polarity markings. A common format is a 3-digit value code plus a voltage letter code: for example, 106C on a tantalum means 10 × 10⁶ pF = 10,000,000 pF = 10µF, voltage code C = 16V. The polarity stripe on a tantalum marks the positive (anode) terminal — this is the reverse of through-hole electrolytic convention, where the stripe marks negative.

Some larger SMD ceramics (0805 and above, particularly high-capacitance types) carry the standard 3-digit code in very small print. A magnifier is often required to read it.

The EIA-198 two-character code is used on some SMD ceramics. In this system, a letter indicates the capacitance value and a number indicates the multiplier. For example, “A5” means 1.0 pF × 10⁵ = 100,000 pF = 100nF. This system requires a lookup table to decode and is less intuitive than the 3-digit system.

SMD Capacitor Identification Quick Reference:

SMD Type	Typical Marking	How to Decode
MLCC (0402, 0603, 0805 standard)	Usually none	BOM/assembly data; LCR meter if unmarked
MLCC (larger, high-value)	3-digit code, e.g. “105”	Same as through-hole 3-digit: 10×10⁵ = 1,000,000pF = 1µF
SMD Tantalum	3-digit code + voltage letter, e.g. “106C”	3-digit value + EIA voltage code; positive stripe = anode
SMD Aluminium (V-chip)	Capacitance + voltage, e.g. “10µF 16V” or “10/16”	Direct reading; negative stripe = cathode
EIA-198 code	Letter + number, e.g. “A5”	Requires EIA-198 lookup table

## Reading Electrolytic and Tantalum Capacitors

Large aluminium electrolytic through-hole capacitors — the cylindrical types with a black or blue sleeve — print their specifications directly on the body because there’s enough room. The convention is straightforward: capacitance in µF, voltage in V, and a stripe or arrow indicating the negative lead. The negative lead is also typically shorter than the positive lead in new-old-stock parts.

For tantalum through-hole capacitors (the small teardrop-shaped yellow or orange parts common in 1980s–90s equipment), the marking is usually a 2- or 3-digit numeric code for capacitance in pF, followed by a letter for tolerance, with the voltage and polarity either printed separately or indicated by a dot or band marking the positive lead.

## Online Tools and Resources for Capacitor Code Identification

Calculators and Decoders

• DigiKey — SMD Capacitor Code Calculator — Handles 3-digit EIA, 4-digit EIA, and EIA-198 two-character codes; fast and authoritative
• Circuitspedia — Ceramic Capacitor Code Calculator — Includes a full look-up table for common 3-digit codes with µF/nF/pF conversions
• GetZenQuery — Capacitor Code Calculator — Decodes colour codes, numeric codes, and letter-number codes in one tool; also converts between pF, nF, and µF
• DigiKey — RC Time Constant Calculator — Not for marking decoding, but essential once you have the value and need to calculate RC circuit behaviour

Reference Articles and Charts

• Electronics Tutorials — Capacitor Colour Codes — The most comprehensive freely available reference for the complete colour band system, covering all five types (J, K, L, M, N) with tables and worked examples
• Engineers Edge — Capacitor Color Code Chart — Clean printable chart covering 4-band and 5-band colour codes; good for workbench reference
• JLCPCB — How to Read SMD Capacitor Codes — Practical SMD-focused guide covering the “90% are unmarked” reality and how to handle polarity on tantalum SMD parts
• AllPCB — Decoding Capacitor Codes Guide — Engineering-oriented guide covering EIA colour bands, 3-digit codes, and EIA-198 SMD codes with real failure case example
• iequalscdvdt.com — Markings and Codes — Exceptionally thorough hobbyist reference covering manufacturer variations, military codes, EIA tables, and the “inconsistency problem” with SMD markings honestly

Component Databases and Datasheets

• DigiKey Ceramic Capacitor Search — Parametric search by value, voltage, dielectric, package; useful for identifying and sourcing when you have a decoded value but no part number
• Murata Product Database — Manufacturer’s database for MLCC identification; search by capacitance, voltage, dielectric (C0G, X7R, X5R), and package

## 5 FAQs: Capacitor Color Code and Identification

Q1: I have a ceramic disc capacitor marked “104” — what is its capacitance, and why isn’t the answer 104 pF?

This is the single most common misread in capacitor identification. The number 104 on a ceramic capacitor is a 3-digit EIA code, not a direct value in picofarads. In this system, the first two digits (10) are the significant figures, and the third digit (4) is the exponent — meaning you multiply 10 by 10⁴ (ten-thousand). The result is 100,000 pF, which equals 100nF or 0.1µF. This is one of the most common capacitor values in electronics, used routinely as a bypass or decoupling cap between a power supply pin and ground on virtually every integrated circuit. Once you understand that the third digit is always an exponent, the system becomes straightforward: 102 = 10 × 100 = 1,000pF = 1nF; 472 = 47 × 100 = 4,700pF = 4.7nF; 221 = 22 × 10 = 220pF.

Q2: I have a capacitor with colour bands but I can’t tell which end to start reading from. How do I orient it?

On most through-hole cylindrical capacitors with colour bands, bands are spaced closer together at one end — start reading from that end. On flat/block-shaped capacitors like mica and some polyester types, bands or dots typically run from top to bottom when the leads point downward. Some manufacturers add a silver or gold band at one end that indicates the direction of reading (start from the opposite end of that band). If the capacitor has teardrop-shaped dots, orient it so the pointed ends of the teardrops face right, then read left-to-right. If there is no obvious directional indicator and the capacitor has five bands, try reading from both ends and check which result gives a value from the standard E6 or E12 series — that’s almost certainly the correct reading direction. When you’re still unsure, measure with a capacitance meter to confirm.

Q3: My capacitor is marked “473J” — what does the letter mean, and does it affect the capacitance?

The number 473 is the value code: 47 × 1,000 = 47,000 pF = 47nF. The letter J is the tolerance code and does not change the nominal capacitance value. J indicates ±5% tolerance, meaning the actual capacitance will be somewhere between 44,650 pF and 49,350 pF. Common tolerance letters you’ll encounter are J (±5%), K (±10%), and M (±20%). For most bypass and decoupling applications, ±10% or ±20% is perfectly acceptable. For timing circuits, active filter networks, or precision applications, ±5% or better is usually required. If you’re replacing a capacitor and the tolerance letter differs between the original and the replacement, the circuit will still work for most applications as long as the capacitance value is the same — just verify the application isn’t timing- or frequency-sensitive.

Q4: I have a large batch of old through-hole capacitors with no markings at all — how do I identify them?

Without any printed markings or colour bands, the only reliable method is direct measurement with an LCR meter or a digital multimeter with a capacitance function. Connect the meter probes to the capacitor terminals (observing polarity for electrolytics), discharge the capacitor first if it might be charged, and read the capacitance value. From the measured value, you can then cross-reference to standard E-series values to identify the nominal rating. An LCR meter also measures ESR and dissipation factor, which can tell you whether the capacitor is still good. For electrolytics with no marking, the body height and diameter can give rough guidance on the capacitance range — a large 25mm can is likely in the 1,000µF–10,000µF range, while a 5mm body is more likely 1µF–47µF. Physical size narrows the field, measurement gives you the answer.

Q5: Why do SMD MLCCs have no markings, and how am I supposed to identify a capacitor that’s already soldered to a board?

The absence of markings on SMD MLCCs is a manufacturing reality, not a convenience feature. The ceramic firing process at 1,000°C+ destroys any pre-applied marking, and post-fire marking adds cost that’s impractical at production volumes of billions of parts per year. For identifying a soldered MLCC, there are three approaches depending on what information you have. If you have the PCB BOM or schematic, that’s the definitive answer — the part number and value are in the documentation. If you have the board assembly data (Gerber files or pick-and-place file), the component value is in the placement data for that designator. If you have neither, desolder the component and measure with smart tweezers (an LCR tweezer meter) or a standard LCR meter — this gives you capacitance and ESR, which together confirm whether the part is functional. A capacitance reading alone won’t tell you the voltage rating or dielectric type (C0G vs. X7R), which is why BOM integrity matters so much in MLCC-heavy designs.

## Putting It All Together: A Practical Identification Workflow

When you’re at the bench with an unknown capacitor, work through this sequence: start with what the physical format tells you (is it an electrolytic with a stripe? a disc ceramic with a 3-digit code? a coloured band tubular?), then read or decode the marking using the appropriate table, and confirm with a measurement if the value is critical or the marking is uncertain.

For vintage equipment with colour bands: identify the capacitor type from its physical form (teardrop, tubular, block), determine reading direction, decode using the colour table above, and cross-reference with the circuit schematic if available.

For modern through-hole ceramics and films: decode the 3-digit EIA code remembering that pF is the base unit and the third digit is an exponent, not a value digit. Add the tolerance letter if present.

For SMD parts: check whether the component has any visible marking at all. If it does, decode as described above. If it doesn’t — which is the majority case for MLCCs — go to the BOM or measure directly. Never guess, and never assume a value just because the physical size matches another component.