Resistor Colour Code Calculator

How to Read Resistor Colour Codes

Resistors use coloured bands painted around their body to indicate their resistance value, tolerance, and sometimes temperature coefficient. Reading the colour code is straightforward once you know the system:

1. Orient the resistor. Hold it so the band grouping is on the left, or the tolerance band (gold or silver) is on the right. The gap between the last digit/multiplier bands and the tolerance band is slightly wider.
2. Read the digit bands. For a 4-band resistor, the first two bands are digits (0–9). For a 5-band or 6-band resistor, the first three bands are digits. Each colour maps to a number: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9.
3. Read the multiplier band. This band tells you what power of 10 to multiply by. Brown = ×10, Red = ×100, Orange = ×1k, Yellow = ×10k, and so on. Gold = ×0.1 and Silver = ×0.01.
4. Read the tolerance band. Gold = ±5%, Silver = ±10%, Brown = ±1%, Red = ±2%. If there is no tolerance band, assume ±20%.
5. 6-band resistors have an extra band for the temperature coefficient, which tells you how the resistance changes with temperature (in ppm/°C).

Example: Brown, Black, Red, Gold = 10 × 100 = 1,000Ω = 1kΩ ±5%.

Resistor Colour Code Chart

This reference table shows every colour and its meaning in each band position. Bookmark it for quick lookups when building circuits.

Colour	Digit	Multiplier	Tolerance	Temp. Coeff.
Black	0	×1Ω	—	250 ppm/°C
Brown	1	×10Ω	±1%	100 ppm/°C
Red	2	×100Ω	±2%	50 ppm/°C
Orange	3	×1kΩ	±0.05%	15 ppm/°C
Yellow	4	×10kΩ	±0.02%	25 ppm/°C
Green	5	×100kΩ	±0.5%	20 ppm/°C
Blue	6	×1MΩ	±0.25%	10 ppm/°C
Violet	7	×10MΩ	±0.1%	5 ppm/°C
Grey	8	×100MΩ	±0.01%	—
White	9	×1GΩ	—	—
Gold	—	×0.1Ω	±5%	—
Silver	—	×0.01Ω	±10%	—

Common Resistor Values for Guitar Pedals

If you’re building guitar effects pedals, you’ll encounter the same handful of resistor values over and over. Below is a reference for common values with their 4-band colour codes (±5%) and typical use. Each row has an anchor link so you can bookmark or share a specific value.

Value	4-band colour code (±5%)	Typical use in pedals
100Ω	Brown-Black-Brown-Gold	Current limiting, emitter degeneration in transistor stages
220Ω	Red-Red-Brown-Gold	LED current limiting at 5V, low-value series resistors
330Ω	Orange-Orange-Brown-Gold	LED current limiting at 5V for higher brightness
470Ω	Yellow-Violet-Brown-Gold	LED current limiting at 9V — the classic pedal indicator LED value (~15mA through a red LED)
680Ω	Blue-Grey-Brown-Gold	LED current limiting at 12V, low-value bias resistors
1kΩ	Brown-Black-Red-Gold	Biasing networks, feedback resistors, op-amp gain setting
1.5kΩ	Brown-Green-Red-Gold	LED current limiting at 18V/24V, emitter resistors
2.2kΩ	Red-Red-Red-Gold	Dim LED indicators (~3mA on 9V), op-amp feedback
3.3kΩ	Orange-Orange-Red-Gold	Gain setting, input resistors in feedback paths
4.7kΩ	Yellow-Violet-Red-Gold	Base biasing in transistor circuits — classic in Fuzz Face and similar designs
6.8kΩ	Blue-Grey-Red-Gold	Collector and bias resistors in transistor stages
10kΩ	Brown-Black-Orange-Gold	The most ubiquitous value in pedal circuits — biasing, voltage dividers, mixing networks, pull-down resistors
22kΩ	Red-Red-Orange-Gold	Input resistors for buffered pedal inputs, biasing networks
33kΩ	Orange-Orange-Orange-Gold	Tone stack resistors, voltage divider biasing
47kΩ	Yellow-Violet-Orange-Gold	Anti-pop pulldown resistors at the input — seen in Boss-style circuits
100kΩ	Brown-Black-Yellow-Gold	Gain setting in feedback loops, bias resistors in JFET and op-amp circuits
220kΩ	Red-Red-Yellow-Gold	Volume/tone pot loading, op-amp feedback in high-gain stages
470kΩ	Yellow-Violet-Yellow-Gold	Bias networks for high-impedance JFET and tube stages
1MΩ	Brown-Black-Green-Gold	Input impedance to preserve guitar signal integrity, bias networks in JFET stages

Once you’ve sorted your components, plan your enclosure layout with Stompbox Layout — a free browser-based tool for placing drill holes with millimetre precision and exporting print-ready PDF or SVG templates.

E-Series Standard Values

Resistor manufacturers don’t make every possible resistance value. Instead, they produce a set of “preferred values” from the E-series, defined by the IEC 60063 standard. Each series divides a decade (1–10) into a specific number of logarithmically spaced steps:

• E12 (12 values per decade) — designed for ±10% tolerance resistors. Values: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82. These are the most common values you’ll find in guitar pedal schematics.
• E24 (24 values per decade) — designed for ±5% tolerance. Adds intermediate values like 11, 13, 16, 20, 24, 30, 36, 43, 51, 62, 75, 91 to the E12 set.
• E48 (48 values per decade) — designed for ±2% tolerance. Used in precision circuits where tighter values matter.
• E96 (96 values per decade) — designed for ±1% tolerance. These are the values typically available in metal-film resistors.

The spacing is logarithmic so that every value in the series is the same percentage step from its neighbours. This means the tolerance bands of adjacent values just barely overlap, ensuring complete coverage of the number line.

SMD Resistor Codes

Surface-mount (SMD) resistors are too small for colour bands, so they use printed numeric codes instead. There are three common marking systems:

• 3-digit code — the first two digits are the significant figures and the third digit is the number of zeros (multiplier). For example, 103 = 10 followed by 3 zeros = 10,000Ω = 10kΩ. The code 4R7 uses “R” as a decimal point, meaning 4.7Ω.
• 4-digit code — similar to 3-digit, but with three significant figures for higher precision. For example, 4702 = 470 followed by 2 zeros = 47,000Ω = 47kΩ.
• EIA-96 code — used on ±1% SMD resistors. A 2-digit number (01–96) maps to a value from the E96 series, followed by a letter indicating the multiplier. For example, 01A = 100 × 1 = 100Ω, and 68C = 499 × 100 = 49.9kΩ.

Frequently Asked Questions

How do I read a resistor colour code?

Hold the resistor with the tolerance band (gold or silver) on the right. Read the colour bands from left to right. For a 4-band resistor: the first two bands are digits, the third band is the multiplier (number of zeros), and the fourth band is the tolerance. For a 5-band resistor: the first three bands are digits, the fourth is the multiplier, and the fifth is the tolerance.

What does a gold band mean on a resistor?

A gold band indicates either ±5% tolerance (when it is the last band) or a ×0.1 multiplier (when it is in the multiplier position). Gold is most commonly seen as the tolerance band on standard 4-band resistors.

What is the difference between 4-band and 5-band resistors?

A 4-band resistor has 2 digit bands, 1 multiplier band, and 1 tolerance band. A 5-band resistor has 3 digit bands, 1 multiplier band, and 1 tolerance band. 5-band resistors offer higher precision (3 significant figures vs 2) and are typically used for tighter tolerance values (±1% or better).

What colour is a 220 ohm resistor?

A 220Ω resistor has the colour bands Red, Red, Brown, Gold for a 4-band resistor (±5% tolerance). Red = 2, Red = 2, Brown = ×10 multiplier, Gold = ±5% tolerance.

What colour is a 1k resistor?

A 1kΩ (1,000Ω) resistor has the colour bands Brown, Black, Red, Gold for a 4-band resistor (±5% tolerance), or Brown, Black, Black, Brown, Brown for a 5-band resistor (±1% tolerance). Brown = 1, Black = 0, Red = ×100 multiplier.

What colour is a 2.2k resistor?

A 2.2kΩ (2,200Ω) resistor has the colour bands Red, Red, Red, Gold for a 4-band resistor (±5% tolerance). Red = 2, Red = 2, Red = ×100 multiplier, Gold = ±5% tolerance.

What colour is a 10k resistor?

A 10kΩ (10,000Ω) resistor has the colour bands Brown, Black, Orange, Gold for a 4-band resistor (±5% tolerance). Brown = 1, Black = 0, Orange = ×1,000 multiplier, Gold = ±5% tolerance.

What colour is a 47k resistor?

A 47kΩ (47,000Ω) resistor has the colour bands Yellow, Violet, Orange, Gold for a 4-band resistor (±5% tolerance). Yellow = 4, Violet = 7, Orange = ×1,000 multiplier, Gold = ±5% tolerance.

What colour is a 100k resistor?

A 100kΩ (100,000Ω) resistor has the colour bands Brown, Black, Yellow, Gold for a 4-band resistor (±5% tolerance). Brown = 1, Black = 0, Yellow = ×10,000 multiplier, Gold = ±5% tolerance.

What colour is a 1M resistor?

A 1MΩ (1,000,000Ω) resistor has the colour bands Brown, Black, Green, Gold for a 4-band resistor (±5% tolerance). Brown = 1, Black = 0, Green = ×100,000 multiplier, Gold = ±5% tolerance.

What is the E24 series?

The E24 series is a set of 24 standard preferred resistance values per decade, designed for ±5% tolerance resistors. The values are: 10, 11, 12, 13, 15, 16, 18, 20, 22, 24, 27, 30, 33, 36, 39, 43, 47, 51, 56, 62, 68, 75, 82, 91. These values are spaced so that the tolerance ranges of adjacent values just overlap.

How do I read an SMD resistor code?

SMD resistors use either 3-digit, 4-digit, or EIA-96 codes. For 3-digit codes (e.g. 103), the first two digits are significant figures and the third is the number of zeros: 103 = 10,000Ω = 10kΩ. For 4-digit codes (e.g. 4702), the first three digits are significant figures and the fourth is the multiplier: 4702 = 47,000Ω = 47kΩ. EIA-96 codes use a 2-digit number plus a letter multiplier.

Need to calculate an LED resistor? Use our LED resistor calculator to find the right current limiting resistor for your indicator LED.