Resistor Color Code Calculator

Decode 4, 5, and 6-band resistor values with tolerance and temperature coefficient

Resistor Configuration

4-band: Standard precision, 5-band: High precision, 6-band: Precision with temperature coefficient

Visual Resistor

black
black
black
gold

Resistor Values

0.00 Ω
Nominal Resistance
±5%
Tolerance
0.00 Ω
Minimum Value
0.00 Ω
Maximum Value

Common Resistor Values

10k
4-band: brown, black, orange, gold
5-band: brown, black, black, red, gold
220Ω
4-band: red, red, brown, gold
5-band: red, red, black, black, gold
1M
4-band: brown, black, green, gold
5-band: brown, black, black, yellow, gold
4.7k
4-band: yellow, violet, red, gold
5-band: yellow, violet, black, brown, gold

Color Value Reference

black
Digit: 0 | Mult: 1
brown
Digit: 1 | Mult: 10 | Tol: 1%
red
Digit: 2 | Mult: 100 | Tol: 2%
orange
Digit: 3 | Mult: 1k
yellow
Digit: 4 | Mult: 10k
green
Digit: 5 | Mult: 100k | Tol: 0.5%
blue
Digit: 6 | Mult: 1000k | Tol: 0.25%
violet
Digit: 7 | Mult: 10000k | Tol: 0.1%
gray
Digit: 8 | Mult: 100000k | Tol: 0.05%
white
Digit: 9 | Mult: 1000000k
gold
| Mult: 0.1 | Tol: 5%
silver
| Mult: 0.01 | Tol: 10%

Band Functions

Digit Bands

First 2-3 bands represent significant digits

Multiplier Band

Multiplies the digit value by power of 10

Tolerance Band

Indicates precision as percentage

Temperature Coeff.

Change per degree Celsius (6-band only)

Reading Tips

Look for larger gap before tolerance band

Metallic colors (gold/silver) are usually tolerance

First band is typically closer to component end

Use multimeter to verify if unsure

6-band resistors have temperature coefficient

Understanding Resistor Color Codes

What are Resistor Color Codes?

Resistor color codes are a standardized system for indicating the electrical resistance value, tolerance, and sometimes temperature coefficient of resistors. This color-coding system was developed in the 1920s to provide a compact way to mark component values on tiny resistors where printed numbers would be too small to read.

How to Read the Codes

  • Identify the reading direction by looking for the larger gap before the tolerance band
  • Read significant digits from the first 2-3 colored bands
  • Apply the multiplier from the next band
  • Note the tolerance percentage from the final band

Mathematical Formulas

4-Band Formula:

R = (10 × Band1 + Band2) × Multiplier ± Tolerance%

5-Band Formula:

R = (100 × Band1 + 10 × Band2 + Band3) × Multiplier ± Tolerance%

6-Band Formula:

Same as 5-band + Temperature Coefficient

Practical Applications

  • Circuit design and component selection
  • Electronics prototyping and breadboarding
  • Quality control in manufacturing
  • Component sorting and inventory management
  • Educational electronics learning