Electrical Resistor Colour Code Value Tolerance

Reference data and engineering information about electrical resistor colour code value tolerance for electrical applications.

electricalresistorcolourcode

Overview

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The resistor color code is an international standard for marking the resistance value and tolerance of axial-lead through-hole resistors. Each colored band on the resistor body encodes a digit, multiplier, or tolerance specification. This system enables quick identification without requiring measurement instruments.

Resistors use either four bands (standard tolerance) or five bands (precision tolerance). The first band is always located nearest one end of the resistor body.

Download and print Resistors - Standard Colors Codes table.

Key Formulas

Four-Band Resistance Value

$R = (D_1 \times 10 + D_2) \times 10^{M}$

where $D_1$ and $D_2$ are the first two significant digits and $M$ is the multiplier exponent.

Five-Band Resistance Value

$R = (D_1 \times 100 + D_2 \times 10 + D_3) \times 10^{M}$

where $D_1$ , $D_2$ , and $D_3$ are the first three significant digits and $M$ is the multiplier exponent.

Actual Resistance Range

$R_{\text{actual}} = R_{\text{nominal}} \times \left(1 \pm \frac{\text{Tolerance}}{100}\right)$

Variables

Symbol	Description	Unit
$R$	Nominal resistance	Ω
$D_n$	Significant digit from color band	—
$M$	Multiplier exponent from color band	—
$R_{\text{actual}}$	Actual resistance within tolerance	Ω

Color Code Reference

13 rows

Standard resistor color code for significant digits, multiplier, and tolerance
Color	Significant Digit	Multiplier	Tolerance
Black	0	×1	—
Brown	1	×10	±1%
Red	2	×100	±2%
Orange	3	×1 k	—
Yellow	4	×10 k	—
Green	5	×100 k	±0.5%
Blue	6	×1 M	±0.25%
Violet	7	×10 M	±0.1%
Grey	8	×100 M	—
White	9	×1 G	—
Gold	—	×0.1	±5%
Silver	—	×0.01	±10%
None	—	—	±20%

Source: engineeringtoolbox.com

Interactive Standard Color Code Chart

The original resistors_standard_color_codes.png image is represented below as numeric color-code data. The multiplier value is shown as a base-10 exponent so gold and silver can be included with the standard digit colors.

Resistors - Standard Color Codes

How to Read Resistor Bands

Four-Band Resistors

Band 1 — First significant digit.
Band 2 — Second significant digit.
Band 3 — Multiplier (power of ten).
Band 4 — Tolerance (gold = ±5%, silver = ±10%, none = ±20%).

Example: Yellow, Violet, Orange, Red → $(4 \times 10 + 7) \times 10^{3} = 47\,000\;\Omega$ with ±2% tolerance.

Five-Band Resistors

Band 1 — First significant digit.
Band 2 — Second significant digit.
Band 3 — Third significant digit.
Band 4 — Multiplier.
Band 5 — Tolerance (brown = ±1%, red = ±2%).

Example: Red, Yellow, White, Orange, Brown → $(2 \times 100 + 4 \times 10 + 9) \times 10^{3} = 249\,000\;\Omega$ with ±1% tolerance.

Calculator

Four-Band Resistance Calculator

Band 1 Digit

Band 2 Digit

Multiplier Exponent

Five-Band Resistance Calculator

Band 1 Digit

Band 2 Digit

Band 3 Digit

Multiplier Exponent

Tolerance(%)

Unit Converter

Electrical Resistance Unit Converter

Resistance(Ω)

Restored Original Source Tables

The following tables are restored from the original source page to preserve the complete reference data.

Resistors - Color Codes

13 rows

Resistors - Color Codes
Color	Significant Figures	Multiplier	Tolerance
Silver		10^-2	+/- 10%
Gold		10^-1	+/- 5%
Black	0	1
Brown	1	10	+/- 1%
Red	2	10^2	+/- 2%
Orange	3	10^3
Yellow	4	10^4
Green	5	10^5	+/- 0.5%
Blue	6	10^6	+/- 0.25%
Violet	7	10^7	+/- 0.1%
Grey	8	10^8
White	9	10^9
None			+/- 20%

Source: engineeringtoolbox.com

Download and print Resistors - Standard Colors Codes table.

Four Band Resistor Calculator

2 rows

Four Band Resistor Calculator
None Brown Red Orange Yellow Green Blue Violet Gray White	None Black Brown Red Orange Yellow Green Blue Violet Gray White	None Black Brown Red Orange Yellow Green Blue Gold Silver	None Brown Red Gold Silver
Band 1 options: None, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White	Band 2 options: None, Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White	Multiplier options: None, Black, Brown, Red, Orange, Yellow, Green, Blue, Gold, Silver	Tolerance options: None, Brown, Red, Gold, Silver
47 kOhm +/- 2%	47 kOhm +/- 2%	47 kOhm +/- 2%	47 kOhm +/- 2%

Source: engineeringtoolbox.com

Five Band Resistor Calculator

2 rows

Five Band Resistor Calculator
None Brown Red Orange Yellow Green Blue Violet Gray White	None Black Brown Red Orange Yellow Green Blue Violet Gray White	None Black Brown Red Orange Yellow Green Blue Violet Gray White	None Black Brown Red Orange Yellow Green Blue Gold Silver	None Brown Red Gold Silver
Band 1 options: None, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White	Band 2 options: None, Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White	Band 3 options: None, Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White	Multiplier options: None, Black, Brown, Red, Orange, Yellow, Green, Blue, Gold, Silver	Tolerance options: None, Brown, Red, Gold, Silver
249 kOhm +/- 1%	249 kOhm +/- 1%	249 kOhm +/- 1%	249 kOhm +/- 1%	249 kOhm +/- 1%

Source: engineeringtoolbox.com

Original Source Images

The following original source images are preserved to avoid losing visual reference material. When an image contains chart or tabular data, its extracted values are represented in the page tables, calculators, or interactive charts; remaining images are retained as visual source references.

electrical resistor color codes Resistors - Standard color codes

Engineering Notes

Reading direction: If the resistor has a gold or silver band, that band is always the tolerance band and should be read from the opposite end. When no metallic band is present, read from the end closest to the first band.
Temperature coefficient: A sixth band (rare) indicates the temperature coefficient in ppm/°C, typically using the same color-to-digit mapping.
Surface-mount devices (SMD): Modern chip resistors use a printed numerical code (e.g., "473" = 47 × 10³ = 47 kΩ) or the EIA-96 marking system rather than color bands.
Standard values: Resistors follow the E-series (E12, E24, E48, E96, E192) preferred-value grids. Not every arbitrary resistance is manufactured; available values follow logarithmic spacing within each decade.
Tolerance stacking: When combining resistors in series or parallel, the resulting tolerance is generally tighter than individual tolerances due to statistical averaging, but worst-case analysis should use simple addition of absolute deviations.

References

Original Source — Engineering ToolBox

Source: engineeringtoolbox.com