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. Here are the most common ones and where you’ll typically find them in a circuit:

• 100Ω (Brown-Black-Brown-Gold) — current limiting, emitter degeneration resistors in transistor stages.
• 470Ω (Yellow-Violet-Brown-Gold) — LED current limiting. At 9V supply, this gives roughly 18mA through a standard LED.
• 1kΩ (Brown-Black-Red-Gold) — biasing networks, feedback resistors, and gain-setting resistors in op-amp circuits.
• 4.7kΩ (Yellow-Violet-Red-Gold) — base biasing in transistor circuits, commonly found in Fuzz Face and similar designs.
• 10kΩ (Brown-Black-Orange-Gold) — the most ubiquitous value in pedal circuits. Used for biasing, voltage dividers, mixing networks, and pull-down resistors.
• 22kΩ (Red-Red-Orange-Gold) — input resistors for buffered pedal inputs, and biasing networks.
• 47kΩ (Yellow-Violet-Orange-Gold) — anti-pop pulldown resistors at the input, commonly seen in Boss-style circuits.
• 100kΩ (Brown-Black-Yellow-Gold) — gain setting in feedback loops, bias resistors in JFET and op-amp circuits.
• 1MΩ (Brown-Black-Green-Gold) — input impedance resistors to ensure high-impedance guitar signal integrity, and 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, SVG, or DXF 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 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 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 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.