Resistor Color Code Chart & Calculator: 4, 5, 6 Band Guide

Reading a color coded resistor is one of the first skills every electronics technician or engineer learns. Those colored bands wrapped around the resistor body aren’t decorative—they encode the resistance value, tolerance, and sometimes temperature coefficient in a standardized system that’s been used since the 1920s. Whether you’re troubleshooting a circuit board or building a project from scratch, understanding resistor colour codes saves time and prevents costly mistakes.

This guide covers everything you need to decode any color coded resistor: the complete color chart, step-by-step reading methods for 4-band, 5-band, and 6-band resistors, calculation examples, common pitfalls, and memory techniques to make identification faster.

Why Resistors Use Color Codes

Resistors are small components—often just a few millimeters long. Printing numerical values directly onto such tiny surfaces would be impractical and hard to read. The resistor colour coding system solves this problem by using colored bands that are easy to apply during manufacturing and visible from any angle.

The system was developed in the 1920s by the Radio Manufacturers Association (RMA) and later standardized internationally by IEC 60062. The same basic approach has remained unchanged for over a century because it works: technicians worldwide can read any color coded resistor using the same chart.

The Complete Resistor Color Code Chart

Every color in the resistor colour system has three possible meanings depending on its position: a digit value (0-9), a multiplier, or a tolerance/temperature coefficient. Here’s the complete reference chart:

Color	Digit	Multiplier	Tolerance	Temp Coefficient
Black	0	×1 (10⁰)	—	250 ppm/°C (U)
Brown	1	×10 (10¹)	±1% (F)	100 ppm/°C (S)
Red	2	×100 (10²)	±2% (G)	50 ppm/°C (R)
Orange	3	×1,000 (10³)	±0.05%	15 ppm/°C (P)
Yellow	4	×10,000 (10⁴)	±0.02%	25 ppm/°C (Q)
Green	5	×100,000 (10⁵)	±0.5% (D)	20 ppm/°C (Z)
Blue	6	×1,000,000 (10⁶)	±0.25% (C)	10 ppm/°C (Z)
Violet	7	×10,000,000 (10⁷)	±0.1% (B)	5 ppm/°C (M)
Gray	8	×100,000,000 (10⁸)	±0.05% (A)	1 ppm/°C (K)
White	9	×1,000,000,000 (10⁹)	—	—
Gold	—	×0.1 (10⁻¹)	±5% (J)	—
Silver	—	×0.01 (10⁻²)	±10% (K)	—
None	—	—	±20% (M)	—

Key observation: The multiplier exponent equals the digit value. Brown represents 1 and has a multiplier of 10¹ (10). Orange represents 3 and has a multiplier of 10³ (1,000). This pattern makes the system easier to memorize.

How to Determine Reading Direction

Before decoding any color coded resistor, you must identify which end to start from. Here are reliable methods:

Method 1: Find the tolerance band. Gold and silver bands only appear as tolerance indicators, never as digit bands. If you see gold or silver, that’s the last band—read from the opposite end.

Method 2: Look for spacing. Many resistors have a larger gap between the multiplier and tolerance bands. The grouped bands are read first.

Method 3: Check band proximity to leads. The first band is typically positioned closer to one lead than the tolerance band is to the other lead.

Method 4: Use logic. If reading one direction gives an impossible or unlikely value (like starting with silver), try the other direction.

When in doubt: Measure with a multimeter. Faded, burnt, or dirty bands can make visual identification unreliable.

Reading 4-Band Color Coded Resistors

The 4-band system is the most common resistor colour code format. It provides two significant digits plus a multiplier and tolerance.

4-Band Structure

Band Position	Meaning
1st Band	First significant digit (0-9)
2nd Band	Second significant digit (0-9)
3rd Band	Multiplier (number of zeros to add)
4th Band	Tolerance

4-Band Calculation Formula

Resistance = (1st digit × 10 + 2nd digit) × Multiplier

4-Band Examples

Example 1: Brown-Black-Red-Gold

• Brown (1) + Black (0) = 10
• Red multiplier = ×100
• 10 × 100 = 1,000Ω (1kΩ)
• Gold tolerance = ±5%
• Actual range: 950Ω to 1,050Ω

Example 2: Yellow-Violet-Orange-Gold

• Yellow (4) + Violet (7) = 47
• Orange multiplier = ×1,000
• 47 × 1,000 = 47,000Ω (47kΩ)
• Gold tolerance = ±5%

Example 3: Green-Blue-Brown-Silver

• Green (5) + Blue (6) = 56
• Brown multiplier = ×10
• 56 × 10 = 560Ω
• Silver tolerance = ±10%

Example 4: Red-Red-Gold-Gold (sub-ohm value)

• Red (2) + Red (2) = 22
• Gold multiplier = ×0.1
• 22 × 0.1 = 2.2Ω
• Gold tolerance = ±5%

Common 4-Band Resistor Values Quick Reference

Color Code	Value
Brown-Black-Brown-Gold	100Ω
Brown-Black-Red-Gold	1kΩ
Brown-Black-Orange-Gold	10kΩ
Brown-Black-Yellow-Gold	100kΩ
Red-Red-Brown-Gold	220Ω
Red-Red-Red-Gold	2.2kΩ
Yellow-Violet-Red-Gold	4.7kΩ
Brown-Green-Yellow-Gold	150kΩ

Reading 5-Band Color Coded Resistors

Precision resistors use 5-band resistor colour codes with three significant digits instead of two. This allows more precise values like 147Ω or 4.99kΩ.

5-Band Structure

Band Position	Meaning
1st Band	First significant digit
2nd Band	Second significant digit
3rd Band	Third significant digit
4th Band	Multiplier
5th Band	Tolerance

5-Band Calculation Formula

Resistance = (1st × 100 + 2nd × 10 + 3rd) × Multiplier

5-Band Examples

Example 1: Brown-Black-Black-Brown-Brown

• Brown (1) + Black (0) + Black (0) = 100
• Brown multiplier = ×10
• 100 × 10 = 1,000Ω (1kΩ)
• Brown tolerance = ±1%

Example 2: Red-Violet-Green-Black-Brown

• Red (2) + Violet (7) + Green (5) = 275
• Black multiplier = ×1
• 275 × 1 = 275Ω
• Brown tolerance = ±1%

Example 3: Yellow-Violet-Black-Red-Brown

• Yellow (4) + Violet (7) + Black (0) = 470
• Red multiplier = ×100
• 470 × 100 = 47,000Ω (47kΩ)
• Brown tolerance = ±1%

Example 4: Brown-Black-Black-Black-Brown

• Brown (1) + Black (0) + Black (0) = 100
• Black multiplier = ×1
• 100 × 1 = 100Ω
• Brown tolerance = ±1%

5-Band Exception: Older/Specialized Resistors

Some older or military-spec 5-band resistors follow a different pattern where the 4th band is tolerance and the 5th band is temperature coefficient. In this case:

• Bands 1-2: Significant digits
• Band 3: Multiplier
• Band 4: Tolerance
• Band 5: Temperature coefficient

If you encounter a 5-band color coded resistor with gold or silver in the 4th position, it likely follows this older format.

Reading 6-Band Color Coded Resistors

High-precision and professional-grade resistors add a sixth band for temperature coefficient, indicating how resistance changes with temperature.

6-Band Structure

Band Position	Meaning
1st Band	First significant digit
2nd Band	Second significant digit
3rd Band	Third significant digit
4th Band	Multiplier
5th Band	Tolerance
6th Band	Temperature Coefficient (ppm/°C)

6-Band Example

Orange-Red-Brown-Brown-Green-Red

• Orange (3) + Red (2) + Brown (1) = 321
• Brown multiplier = ×10
• 321 × 10 = 3,210Ω (3.21kΩ)
• Green tolerance = ±0.5%
• Red temp coefficient = 50 ppm/°C

The temperature coefficient tells you how much the resistance changes per degree Celsius. A 50 ppm/°C rating means for every 1°C temperature change, the resistance changes by 50 parts per million (0.005%).

Temperature Coefficient Reference

Color	Temp Coefficient
Black	250 ppm/°C
Brown	100 ppm/°C
Red	50 ppm/°C
Orange	15 ppm/°C
Yellow	25 ppm/°C
Green	20 ppm/°C
Blue	10 ppm/°C
Violet	5 ppm/°C
Gray	1 ppm/°C

Special Cases and Exceptions

Zero-Ohm Resistors

A color coded resistor with a single black band is a zero-ohm resistor—essentially a wire jumper packaged as a resistor for automated assembly. These connect PCB traces and allow the same pick-and-place equipment to install both resistors and jumpers.

3-Band Resistors

Three-band resistors omit the tolerance band entirely, defaulting to ±20% tolerance. These are rarely used today but may appear in older equipment:

• Band 1: First digit
• Band 2: Second digit
• Band 3: Multiplier
• Tolerance: Assumed ±20%

High-Voltage Resistor Color Substitutions

In high-voltage resistors, gold and silver bands are sometimes replaced with yellow and gray to prevent metallic particles in the coating. If you see unexpected yellow or gray bands in tolerance positions, the resistor may be a high-voltage type.

Wide Tolerance Band

Some manufacturers make the tolerance band 1.5 to 2 times wider than other bands to help identify reading direction. This isn’t universal, but when present, it’s a helpful indicator.

Memorizing the Resistor Colour Code

Several memory techniques help engineers quickly recall resistor colour values without constantly referencing charts.

The Rainbow Method

The digit colors from 2 (red) through 7 (violet) follow rainbow order: Red, Orange, Yellow, Green, Blue, Violet. Add black (0) and brown (1) at the beginning, then gray (8) and white (9) at the end:

Black → Brown → [Rainbow: Red through Violet] → Gray → White

Mnemonic Phrases

The classic mnemonic uses the first letter of each color in order:

Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White

Appropriate mnemonics include:

• “Big Beautiful Roses Occupy Your Garden But Violets Grow Wild”
• “Bad Beer Rots Our Young Guts But Vodka Goes Well”
• “Better Buy Resistors Or Your Grid Bias Voltages Go West”

The Multiplier Pattern

Remember: the multiplier exponent equals the color’s digit value.

• Brown = 1 = ×10¹ = ×10
• Red = 2 = ×10² = ×100
• Orange = 3 = ×10³ = ×1,000

This pattern eliminates memorizing multipliers separately.

Practice Makes Permanent

After sorting a few hundred resistors by value, most technicians develop automatic color-to-number recognition. The brain starts seeing “brown-black-orange” and immediately reading “10k” without conscious calculation.

Step-by-Step Color Code Calculation Process

Follow this procedure for any color coded resistor:

Step 1: Identify the number of bands (3, 4, 5, or 6).

Step 2: Determine reading direction using tolerance band position or spacing.

Step 3: For 4-band resistors:

• Write down the first two digits
• Apply the multiplier
• Note the tolerance

Step 4: For 5-band resistors:

• Write down the first three digits
• Apply the multiplier (4th band)
• Note the tolerance (5th band)

Step 5: For 6-band resistors:

• Follow 5-band procedure
• Note temperature coefficient (6th band)

Step 6: Calculate the tolerance range:

• Minimum = Value – (Value × Tolerance%)
• Maximum = Value + (Value × Tolerance%)

Step 7: When uncertain, verify with a multimeter.

Common Mistakes When Reading Resistor Colour Codes

Mistake 1: Reading Backwards

The most common error is starting from the wrong end. Always locate the tolerance band first (gold, silver, or precision colors) and read from the opposite end.

Mistake 2: Confusing Brown and Orange

Under certain lighting, brown and orange can look similar. Brown has a darker, more reddish tone while orange is brighter and more yellowish. If a value seems wrong, double-check these two colors.

Mistake 3: Missing the Band Count

Mistaking a 5-band resistor for a 4-band (or vice versa) gives completely wrong values. Count bands carefully before calculating.

Mistake 4: Ignoring Faded or Burnt Bands

Heat-damaged resistors may have discolored bands. If colors look unusual or the calculated value seems implausible for the circuit, measure with a multimeter instead of trusting visual identification.

Mistake 5: Forgetting Sub-Ohm Multipliers

Gold (×0.1) and silver (×0.01) multipliers create values below 10Ω. These are easy to overlook if you’re only thinking about the “add zeros” pattern.

Tolerance: What It Means for Your Circuit

The tolerance band on a color coded resistor specifies the manufacturing precision—how much the actual resistance can deviate from the marked value.

Tolerance Values and Their Meaning

Tolerance	Color	Letter Code	Actual Range for 1kΩ
±0.05%	Gray	A	999.5Ω – 1000.5Ω
±0.1%	Violet	B	999Ω – 1001Ω
±0.25%	Blue	C	997.5Ω – 1002.5Ω
±0.5%	Green	D	995Ω – 1005Ω
±1%	Brown	F	990Ω – 1010Ω
±2%	Red	G	980Ω – 1020Ω
±5%	Gold	J	950Ω – 1050Ω
±10%	Silver	K	900Ω – 1100Ω
±20%	None	M	800Ω – 1200Ω

When Tolerance Matters

For most digital circuits (pull-up resistors, LED current limiters), ±5% or even ±10% tolerance is perfectly acceptable. The exact value doesn’t significantly affect circuit operation.

For precision applications—voltage dividers, feedback networks, filters, timing circuits—tighter tolerances become important. A ±1% resistor colour specification ensures consistent circuit behavior across production units.

Rule of thumb: Default to ±1% tolerance for new designs. The cost difference from ±5% parts is negligible, and the improved precision eliminates potential issues.

Online Resistor Color Code Calculators

When speed matters or you want to verify manual calculations, online calculators provide instant results.

Recommended Calculator Tools

DigiKey Resistor Color Code Calculator: digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code

All About Circuits Calculator: allaboutcircuits.com/tools/resistor-color-code-calculator/

Resistor Color Code Calc: resistorcolorcodecalc.com

Calculator.net Resistor Calculator: calculator.net/resistor-calculator.html

These tools support 3, 4, 5, and 6-band color coded resistor identification with visual feedback and tolerance range calculations.

Useful Resources

Printable Color Code Charts

EEPower Resistor Guide: eepower.com/resistor-guide/resistor-standards-and-codes/resistor-color-code/

Blue Point Engineering Chart (PDF): Search “resistor color code chart PDF” for downloadable reference sheets

Component Databases

DigiKey: digikey.com (parametric search by resistance value)

Mouser: mouser.com (extensive filtering options)

LCSC: lcsc.com (competitive pricing on common values)

Mobile Apps

Several smartphone apps use camera recognition to identify resistor colour codes automatically. Search “resistor color code” in your app store for current options.

Educational Resources

Electronics Tutorials: electronics-tutorials.ws/resistor/res_2.html

Resistor Guide: eepower.com/resistor-guide/

Frequently Asked Questions

What do the colors on a resistor mean?

The colored bands on a color coded resistor represent its electrical specifications. The first two or three bands indicate significant digits of the resistance value. The next band is a multiplier that determines the number of zeros to add. The final band shows tolerance (how much the actual value can vary from the marked value). On 6-band resistors, an additional band indicates temperature coefficient—how resistance changes with temperature.

How do I know which direction to read resistor colour codes?

Start by locating the tolerance band, which is typically gold (±5%), silver (±10%), or a precision color like brown (±1%). This band is always at one end of the color coded resistor. Read the other bands starting from the opposite end. If no gold or silver band exists, look for the larger gap between bands—the tolerance band has more spacing from its neighbor. When still uncertain, try reading both directions and see which gives a standard value from the E-series (1.0, 1.2, 1.5, 2.2, 3.3, 4.7, etc.).

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

Four-band resistors have two significant digits, giving values like 10Ω, 47Ω, or 100Ω. Five-band resistors have three significant digits, allowing more precise values like 102Ω, 475Ω, or 147Ω. The extra precision comes with tighter tolerance—5-band resistors are typically ±1% or better, while 4-band types are usually ±5% or ±10%. For most general-purpose circuits, 4-band resistor colour coding is sufficient. Precision analog circuits, voltage references, and measurement applications benefit from 5-band precision.

Why do some resistors have 6 color bands?

Six-band resistors include a temperature coefficient specification as the final band. This tells engineers how much the resistance value changes per degree Celsius of temperature change, measured in parts per million (ppm/°C). A color coded resistor with 50 ppm/°C (red 6th band) changes 0.005% per degree. This matters for precision circuits where temperature variations could affect performance—instrumentation, calibration equipment, and measurement systems. The lower the ppm value, the more stable the resistor across temperature ranges.

Can I trust color codes on old or damaged resistors?

Not always. Heat exposure can discolor bands, making brown look more orange or causing bands to fade entirely. Physical damage, dirt, and oxidation also affect readability. If a color coded resistor looks questionable—bands appear faded, colors seem off, or the calculated value doesn’t make sense for the circuit—use a multimeter to measure actual resistance. This is especially important for repair work where incorrect component identification could cause further problems. For critical applications, always verify with measurement rather than relying solely on visual identification.

Conclusion

The resistor colour code system has served electronics for over a century because it elegantly solves the problem of marking tiny components with readable values. Once you understand the basic structure—digit bands, multiplier, tolerance—reading any color coded resistor becomes straightforward.

Key points to remember:

• Always identify the tolerance band first to establish reading direction
• 4-band resistors have two significant digits; 5-band have three
• The multiplier exponent equals the color’s digit value
• When in doubt, measure with a multimeter
• Practice with real resistors accelerates recognition speed

Keep a color code chart at your workbench until the values become automatic. Most engineers reach the point where they see colored bands and immediately read the value without conscious calculation. That fluency comes from repetition, not memorization—the more resistors you handle, the faster identification becomes.

Whether you’re a student learning electronics, a hobbyist building projects, or a professional debugging circuits, mastering the resistor colour code is fundamental knowledge that you’ll use throughout your career.