Resistor Color Code Calculator

Decode resistor values by selecting the color bands. Click on each band to choose its color and instantly calculate the resistance value, tolerance, and temperature coefficient.

Resistor Type

Interactive Resistor

Select Color:

Calculated Values

Resistance
100 Ω
Tolerance
±5%
Range
95 - 105 Ω

Color Code Reference

Color Digit Multiplier Tolerance Temp Coeff (ppm/°C)
Black 0 ×1 - -
Brown 1 ×10 ±1% 100
Red 2 ×100 ±2% 50
Orange 3 ×1K - 15
Yellow 4 ×10K - 25
Green 5 ×100K ±0.5% 20
Blue 6 ×1M ±0.25% 10
Violet 7 ×10M ±0.1% 5
Gray 8 ×100M ±0.05% 1
White 9 ×1G - -
Gold - ×0.1 ±5% -
Silver - ×0.01 ±10% -

How to Read Resistor Color Codes

4-Band Resistors

  • Band 1: First digit
  • Band 2: Second digit
  • Band 3: Multiplier
  • Band 4: Tolerance

Formula: (Band1 × 10 + Band2) × Multiplier

5-Band Resistors

  • Band 1: First digit
  • Band 2: Second digit
  • Band 3: Third digit
  • Band 4: Multiplier
  • Band 5: Tolerance

Formula: (Band1 × 100 + Band2 × 10 + Band3) × Multiplier

6-Band Resistors

  • Band 1: First digit
  • Band 2: Second digit
  • Band 3: Third digit
  • Band 4: Multiplier
  • Band 5: Tolerance
  • Band 6: Temperature coefficient

Reading Tips

  • Start from the band closest to one end
  • Tolerance band is usually gold or silver
  • If unsure, try both orientations
  • Use a multimeter to verify
Related Calculators
Common Resistor Values
E12 Series (10% tolerance)

1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2

E24 Series (5% tolerance)

1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1

Standard Multipliers
  • 1 Ω, 10 Ω, 100 Ω
  • 1 kΩ, 10 kΩ, 100 kΩ
  • 1 MΩ, 10 MΩ
Quick Tips
Identification
  • Gold/silver bands are usually tolerance
  • Start from the opposite end of tolerance
  • Brown band is often first digit (1)
  • Black is never a first digit
Verification
  • Use a multimeter to confirm
  • Check if value makes sense in circuit
  • Consider tolerance when measuring
  • Temperature affects resistance

Frequently Asked Questions

Start reading from the end opposite to the tolerance band (usually gold or silver). If there's no clear tolerance band, look for the band closest to one end - this is typically the first digit. The tolerance band is usually separated by a larger gap from the other bands. If you're still unsure, try reading from both ends and see which gives a standard resistor value.

4-band resistors provide basic resistance and tolerance information with 5-10% accuracy. 5-band resistors add a third digit for more precise values (typically 1-2% tolerance). 6-band resistors include all the above plus a temperature coefficient band, indicating how much the resistance changes with temperature. More bands generally mean higher precision and cost.

This is normal due to manufacturing tolerance. A 100Ω resistor with ±5% tolerance can measure anywhere from 95Ω to 105Ω and still be within specification. Temperature, age, and measurement conditions also affect readings. If the measured value is far outside the tolerance range, the resistor may be damaged or you might be reading the colors incorrectly.