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Resistor Color Code Calculator

Pick the color bands to instantly get the resistance (Ω) and tolerance. Supports 4, 5 and 6-band resistors.

Resistance
1 kΩ ± 5%

Disclaimer: This calculator is provided for general informational and educational purposes only, on an “as is” basis and without any warranty of accuracy or fitness for a particular purpose. Results may contain errors — always verify independently before relying on them in real designs. PartAndStock accepts no liability for any loss or damage arising from use of this tool, including when embedded on third-party sites.

How to use

  1. 1Select the number of bands on your resistor (4, 5 or 6).
  2. 2Hold the resistor so the tolerance band (usually gold or silver, often slightly spaced) is on the right.
  3. 3Pick each band's color from left to right from its menu; the value and tolerance are calculated instantly.

How it works

Select the colored bands on your resistor to instantly find its resistance value, tolerance and temperature coefficient.

First bands are digits, next band is the multiplier, last band is tolerance. 4-band: (digit1 digit2) × multiplier ± tolerance. 5-band: (digit1 2 3) × multiplier ± tolerance.

How the color code works

The color code is an international standard (IEC 60062) that shows the value of resistors too small to print numbers on, using colored bands. Each color maps to a digit, a multiplier or a tolerance percentage. The first bands are the significant digits, the multiplier band is the power of ten, and the last band is the manufacturing tolerance.

Tips and common mistakes

The most common mistake is reading the resistor backwards: use the tolerance band (gold/silver) as a reference and always keep it on the right. On precise 5-band resistors the first THREE bands are digits — don't confuse them with 4-band. Colors can fade on old or overheated resistors, so verify with a multimeter if unsure.

Worked examples

  • Brown–Black–Red–Gold (4-band): 10 × 100 = 1,000 Ω = 1 kΩ ±5%
  • Red–Red–Brown–Gold (4-band): 22 × 10 = 220 Ω ±5%
  • Brown–Black–Black–Brown–Brown (5-band): 100 × 10 = 1,000 Ω = 1 kΩ ±1%

Resistor Color Code Chart

ColorDigitMultiplierTolerance
Black0×1
Brown1×10±1%
Red2×100±2%
Orange3×1 k
Yellow4×10 k
Green5×100 k±0.5%
Blue6×1 M±0.25%
Violet7×10 M±0.1%
Gray8×100 M±0.05%
White9×1 G
Gold×0.1±5%
Silver×0.01±10%

Frequently Asked Questions

How do you read a 4-band resistor?+
The first two bands are digits, the third is the multiplier, the fourth is tolerance. E.g. brown-black-red-gold = 10 × 100 = 1000 Ω (1 kΩ) ± 5%.
What is the difference between 5-band and 4-band?+
5-band resistors use the first three bands as digits, the fourth as multiplier and the fifth as tolerance; they are used for more precise (usually 1%) resistors.
What do gold and silver bands mean?+
In the multiplier position gold means ×0.1 and silver ×0.01. In the tolerance position gold means ±5% and silver ±10%.
What is the 6th band for?+
On 6-band resistors the last band is the temperature coefficient (ppm/°C) — it shows how much the resistance changes with temperature, which matters in precision applications.
Why don't SMD resistors use a color code?+
Surface-mount (SMD) resistors use a numeric code instead of colors. You can decode them with our SMD resistor code calculator.

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