Color Code Resistor Calculator

Quickly decode electronic resistor color bands and calculate resistance values with our interactive calculator. Perfect for electronics engineers, students, hobbyists, and technicians working with circuit components.

Brown-Black-Red-Gold → 1 kΩ ±5%

Orange-Orange-Black-Red-Brown → 330 Ω ±1%

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Resistor Color Code Calculator

Use this interactive calculator to decode resistor color bands or select colors to find the correct resistor for your electronic project.

Resistor Type:

1st Band (1st Digit):

2nd Band (2nd Digit):

3rd Band (Multiplier):

4th Band (Tolerance):

Resistor Visualization

Calculated Values:

Resistance:

Tolerance:

Tolerance Range:

NaN Ω to NaN Ω

E24 Series: The resistance value falls within the E24 series of standard values, which is typical for resistors with ±5% tolerance.

Reading Resistor Color Codes:

Hold the resistor with the tolerance band (gold/silver) to the right
Read the color bands from left to right
The first two bands represent the significant digits
The next band is the multiplier (how many zeros to add)
The last band indicates tolerance

Resistor Color Code Chart

This comprehensive chart shows all color codes used for electronic resistors, including their corresponding values.

Color	1st & 2nd Bands (Digit Value)	3rd Band (for 5 & 6-band)	Multiplier	Tolerance	Temp. Coefficient (ppm/°C)
Black	0	0	×1	-	250
Brown	1	1	×10	±1%	100
Red	2	2	×100	±2%	50
Orange	3	3	×1K	-	15
Yellow	4	4	×10K	-	25
Green	5	5	×100K	±0.5%	20
Blue	6	6	×1M	±0.25%	10
Violet	7	7	×10M	±0.1%	5
Grey	8	8	×100M	±0.05%	1
White	9	9	×1G	-	-
Gold	-	-	×0.1	±5%	-
Silver	-	-	×0.01	±10%	-
None	-	-	-	±20%	-

How to Read Resistor Color Codes

Understanding Resistor Bands

Electronic resistors use colored bands to indicate their resistance value, tolerance, and sometimes temperature coefficient. Learning to read these bands is essential for electronics work.

Types of Resistors by Band Count:

4-Band Resistors (Most Common)

1st band: First digit
2nd band: Second digit
3rd band: Multiplier (power of 10)
4th band: Tolerance

5-Band Resistors (Higher Precision)

1st band: First digit
2nd band: Second digit
3rd band: Third digit
4th band: Multiplier
5th band: Tolerance

6-Band Resistors (Highest Precision)

1st band: First digit
2nd band: Second digit
3rd band: Third digit
4th band: Multiplier
5th band: Tolerance
6th band: Temperature coefficient

Example Calculations:

4-Band Example: Brown-Black-Red-Gold

1st band (Brown) = 1
2nd band (Black) = 0
3rd band (Red) = ×100
4th band (Gold) = ±5%
Result: 10 × 100 = 1,000Ω or 1kΩ ±5%

5-Band Example: Blue-Grey-Red-Brown-Green

1st band (Blue) = 6
2nd band (Grey) = 8
3rd band (Red) = 2
4th band (Brown) = ×10
5th band (Green) = ±0.5%
Result: 682 × 10 = 6,820Ω or 6.82kΩ ±0.5%

Tips for Reading Resistors

Proper Orientation

Always hold the resistor with the tolerance band (gold or silver, or the band spaced farther apart) on the right side.

Band Count Identification

Count the total number of bands to determine whether it's a 4, 5, or 6-band resistor before attempting to read the value.

Color Recognition

In poor lighting, colors like brown/red or blue/violet can be difficult to distinguish. Use good lighting or a multimeter when in doubt.

Standard Values

If your calculated value seems unusual, check if it's a standard E-series value for the given tolerance. Most resistors come in standard series (E12, E24, E96, etc.).

Visual Mnemonics

To remember color values, many use the mnemonic: "BB ROY G. BIV" (Black, Brown, Red, Orange, Yellow, Green, Blue, Indigo/Violet) for the values 0-7.

Understanding Tolerance

Tolerance indicates how much the actual resistance may vary from the nominal value:

A 1kΩ resistor with ±5% tolerance can actually measure between 950Ω and 1,050Ω
Tighter tolerances (±1%, ±0.5%, etc.) are used in precision circuits
Most general-purpose applications use ±5% tolerance resistors

Understanding E-Series Standard Values

Resistors are manufactured in standardized values called E-series. The number following "E" indicates how many values are available per decade (power of 10):

•
E12 (±10% tolerance): 12 values per decade10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82
•
E24 (±5% tolerance): 24 values per decadeIncludes E12 values plus: 11, 13, 16, 20, 24, 30, 36, 43, 51, 62, 75, 91
•
E96 (±1% tolerance): 96 values per decadeUsed for precision resistors with much finer gradations

These standard values repeat for each decade (×1, ×10, ×100, ×1k, ×10k, etc.)

Common Resistor Values and Applications

While resistors come in many values, certain values are more commonly used in electronic circuits. Here are some of the most frequently used resistors and their typical applications:

Common Resistor Values

Pull-up/Pull-down Resistors

1kΩ - 10kΩ: Common for digital circuits
4.7kΩ: Popular for I²C bus pull-ups
10kΩ: Standard for many microcontroller inputs

LED Current-Limiting Resistors

220Ω - 470Ω: Common for 5V supply
1kΩ - 2.2kΩ: Used with lower-current LEDs

Audio Circuits

1kΩ - 100kΩ: Input/output impedance
470Ω: Common in audio amplifier feedback networks

Resistor Applications

Voltage Dividers

Used to reduce voltage by a fixed ratio:

Sensor interfaces
Reference voltage generation
Level shifting

Current Limiting

Protect components from excessive current:

LED circuits
Transistor biasing
Protection for sensitive components

Timing Circuits

Used with capacitors in RC circuits:

Oscillators
Filters
Timers (like 555 timer circuits)

Power Ratings

Aside from resistance value, resistors also have power ratings that indicate how much power they can safely dissipate without overheating. Common power ratings include:

1/8 Watt (0.125W)

Small resistors used in low-power signal circuits and digital electronics

1/4 Watt (0.25W)

Most common size for general-purpose electronics and DIY projects

1/2 Watt (0.5W) and higher

Used in power circuits, motor controls, and high-current applications

To calculate power in a resistor: P = I² × R (where I is current and R is resistance) or P = V² / R (where V is voltage)

Frequently Asked Questions

What is a resistor color code?

A resistor color code is a system of colored bands used on resistors to indicate their resistance value, tolerance, and sometimes temperature coefficient. The system uses a sequence of colored bands, where each color represents a specific number or value according to a standardized code. This allows electronics professionals and hobbyists to quickly identify resistor values without using measuring instruments.

How do I read a 4-band resistor color code?

To read a 4-band resistor color code, follow these steps: 1) Hold the resistor with the tolerance band (usually gold or silver) to the right. 2) The first two bands represent the first and second significant digits. 3) The third band is the multiplier, indicating how many zeros to add or the power of 10 to multiply by. 4) The fourth band indicates tolerance. For example, if the bands are brown, black, red, gold, this represents 1, 0, followed by two zeros (10²), or 1,000 ohms (1kΩ) with a tolerance of ±5%.

What is the difference between 4-band, 5-band, and 6-band resistors?

The main differences between these resistor types are the precision and additional information they provide. 4-band resistors have two significant digits, a multiplier, and a tolerance band. 5-band resistors have three significant digits, a multiplier, and a tolerance band, allowing for more precise resistance values. 6-band resistors add a sixth band that indicates the temperature coefficient, showing how much the resistance value changes with temperature variations.

How do I calculate the actual resistance range of a resistor?

To calculate the actual resistance range, you need to know the nominal resistance value and tolerance. For example, a 1kΩ resistor with a tolerance of ±5% would have a minimum value of 950Ω (1000 - 5%) and a maximum value of 1050Ω (1000 + 5%). The calculation is: Minimum value = Nominal value × (1 - Tolerance/100) and Maximum value = Nominal value × (1 + Tolerance/100).

Why do resistors have different tolerances?

Resistors have different tolerances to serve various applications and cost considerations. General-purpose circuits often use resistors with ±5% or ±10% tolerance because precise values aren't critical. Precision applications like instrumentation, audio equipment, or reference circuits require tighter tolerances (±1% or better) for accurate performance. Higher precision resistors cost more to manufacture, so designers choose the appropriate tolerance based on the circuit requirements and budget constraints.

What does the temperature coefficient mean for resistors?

The temperature coefficient indicates how much a resistor's value changes with temperature, measured in parts per million per degree Celsius (ppm/°C). For example, a 1kΩ resistor with a temperature coefficient of 100 ppm/°C will change by 0.1Ω for each 1°C temperature change. Lower values (like 15 ppm/°C) indicate more stable resistors whose values change less with temperature fluctuations. This specification is important for precision circuits that operate across varying temperature environments or where stability is critical.

Master Resistor Color Codes Today

Use our interactive calculator to quickly identify resistor values and build your electronics knowledge

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