Resistor Colour Code Calculator

Select the colour of each band to read the resistance value and tolerance from a 4-band, 5-band or 6-band resistor. The calculator decodes the IEC 60062 colour code instantly.

Select a colour for each band.

Resistor Colour Code Reference

The table below shows the digit value, multiplier and tolerance for each colour band, per IEC 60062.

Colour Digit Multiplier Tolerance Tempco (ppm/K)
Black0×1----
Brown1×10±1%100
Red2×100±2%50
Orange3×1 k--15
Yellow4×10 k--25
Green5×100 k±0.5%--
Blue6×1 M±0.25%10
Violet7×10 M±0.1%5
Grey8×100 M±0.05%--
White9×1 G----
Gold--×0.1±5%--
Silver--×0.01±10%--

How It Works

The colour-band formula

Each colour represents a digit (0-9) or a multiplier. The resistance value is calculated as follows:

  • 4-band: Resistance = (D1 × 10 + D2) × Multiplier
  • 5-band: Resistance = (D1 × 100 + D2 × 10 + D3) × Multiplier
  • 6-band: Same as 5-band, plus a temperature coefficient band

Worked example

A 4-band resistor with bands Brown, Black, Red, Gold:

  • D1 = Brown = 1; D2 = Black = 0
  • Multiplier = Red = ×100
  • Resistance = (1 × 10 + 0) × 100 = 1,000 Ω (1 kΩ)
  • Tolerance = Gold = ±5%

A 5-band resistor with bands Brown, Black, Black, Brown, Brown:

  • D1=1, D2=0, D3=0; Multiplier = Brown = ×10
  • Resistance = (100 + 0 + 0) × 10 = 1,000 Ω (±1%)

Frequently Asked Questions

How do I read resistor colour bands?

Hold the resistor so that the tolerance band (usually gold or silver) is on the right. Read the remaining bands left to right: the first two (or three, for a 5/6-band part) are digits, the next band is the multiplier, and the last is the tolerance. Multiply the digit number by the multiplier to get the resistance in ohms.

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

A 4-band resistor has two digit bands, one multiplier and one tolerance band. This gives two significant figures and suits general-purpose parts. A 5-band resistor adds a third digit band for greater precision (e.g. ±1% and ±2% parts). A 6-band resistor adds a sixth band for the temperature coefficient (tempco), indicating how the resistance changes with temperature in parts per million per kelvin (ppm/K).

What does the tolerance band mean?

The tolerance band tells you the acceptable range of the actual resistance value. Gold (±5%) on a 1 kΩ resistor means the real resistance will be between 950 Ω and 1,050 Ω. Precision resistors use brown (±1%), red (±2%), or tighter tolerance bands such as green (±0.5%) and blue (±0.25%).

What is the Black Brown Red mnemonic for the colour code?

A common memory aid for the digit colours in order (0 to 9) is: "Better Be Right Or Your Great Big Venture Goes Wrong" (Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White). Several alternatives exist; choose the one that sticks best for you.

What is the temperature coefficient band on a 6-band resistor?

The sixth band indicates how much the resistance changes with temperature, measured in parts per million per kelvin (ppm/K). Brown indicates 100 ppm/K, red 50 ppm/K, and violet the tightest standard rating of 5 ppm/K. A lower ppm/K value means the resistor is more stable across a temperature range, which matters in precision circuits and measurement equipment.

Related Calculators

Continue with these related electrical tools

LED Resistor Calculator

Series resistor for an LED: ohms, power and nearest standard value

Ohm's Law Calculator

Solve voltage, current, resistance and power from any two

Watts Amps Volts Calculator

Convert between watts, volts and amps (DC, 1-phase, 3-phase)

Embed This Calculator

Add this free calculator to your website. Copy the code below and paste it into your page.

Electrical Calculators Electrical Calculators

Fast, free calculators for electricians and engineers

More Calculators

© 2026 Electrical Calculators. All rights reserved.

Privacy Policy Terms of Service Cookie Policy