Resistor Color Code Calculator for 3, 4, 5, and 6 band resistors. Decode resistance, tolerance, and temperature coefficient with formulas, examples, FAQs, and references.

Resistor Color Code Calculator - 4, 5 and 6 Band Chart

Agarapu Ramesh — Editor and content reviewer
Editorially reviewed Reviewed by Agarapu Ramesh, science educator (chemistry). LinkedIn
Last reviewed: May 2026 | Standard electrical engineering formulas

Resistor bands are a compact label, not a personality test. The first bands give digits, the multiplier band adds zeros, and the tolerance band tells you how far the real part may wander.

Formula at a glance

  • 4-band: R = (digit1 x 10 + digit2) x multiplier
  • 5-band: R = (digit1 x 100 + digit2 x 10 + digit3) x multiplier
  • range = R +/- tolerance

Field note: Color codes are great until the part has cooked on a board for ten years. A meter reading wins when the bands look suspicious.

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Formulas

4-BandR = (D1·10 + D2) × Mul
5-BandR = (D1·100 + D2·10 + D3) × Mul
RangeMin/Max = R ± Tolerance

Quick Reference: Color Code

ColorDigitMultiplierTol
Black0×1-
Brown1×10±1%
Red2×100±2%
Orange3×1k-
Yellow4×10k-
Green5×100k±0.5%
Blue6×1M±0.25%
Violet7×10M±0.1%
Grey8×100M±0.05%
White9×1G-
Gold-×0.1±5%
Silver-×0.01±10%

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How to use the Resistor Color Code Calculator

Use this as a bench check, then compare it with the part marking, tolerance and a meter reading when the circuit matters. Small components are cheap. Bad assumptions are not.

Worked example

Example: yellow, violet, red, gold means 47 x 100 = 4,700 ohms, or 4.7 k ohms, with +/-5% tolerance.

Practical checks before you trust the number

  • Read from the end with the tolerance band, usually gold, silver, brown, red or green.
  • Burnt or faded bands are not trustworthy. Measure the part.
  • Precision circuits usually use 1% or better parts.

Common mistake

Color codes are great until the part has cooked on a board for ten years. A meter reading wins when the bands look suspicious.

Sources and references

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Frequently Asked Questions

Choose the number of bands and set each band color. The resistor calculator returns resistance, tolerance, and temperature coefficient when applicable.

Yes. Color and colour are different spellings for the same resistor band system.

A 4 color resistor code has two digit bands, one multiplier band, and one tolerance band.

It is a reference table that maps each color to its digit, multiplier, tolerance, or temperature coefficient.

Read it left to right. Hold the resistor with the tolerance band (gold or silver) on your right. The first two bands are significant digits, the third is the multiplier (power of 10), and the fourth is tolerance. Example: brown-black-red-gold means 1, 0, ×100 = 1000 Ω = 1 kΩ ±5%. I tell my juniors to keep a printed code chart on the bench until the colors become second nature, because misreading red as orange happens to everyone in low light.

Gold and silver almost always sit in the tolerance position. Gold means ±5% accuracy, silver means ±10%. If gold or silver appears as the third band (the multiplier) instead, it represents a divider: gold = ×0.1 and silver = ×0.01, used for sub-ohm resistors like 4.7 Ω or 0.22 Ω. So check the orientation first; misplacing the gold band has caused several wrong builds in our lab.

Tolerance is a percentage of the nominal value, given by the last band: gold ±5%, silver ±10%, brown ±1%, red ±2%, green ±0.5%. Multiply the nominal resistance by the tolerance and you get the allowed range. Example: a 1 kΩ ±5% resistor can read anywhere between 950 Ω and 1050 Ω and still be in spec. For house dimmer circuits and LED drivers we usually pick ±1% so the brightness stays consistent across fittings.

A 4-band resistor uses two significant digits plus a multiplier and tolerance, while a 5-band one uses three significant digits plus multiplier and tolerance. The extra band gives you finer values like 4.99 kΩ instead of just 4.7 kΩ or 5.1 kΩ. Precision resistors (1% or better) are usually 5-band. So if you spot five color bands on a small body, treat the third one as a digit, not a multiplier — that mistake costs us hours of debugging.

A 10 kΩ resistor in the 4-band scheme reads brown-black-orange-gold (1, 0, ×1000, ±5%). In a 5-band 1% precision part, the same value is brown-black-black-red-brown (1, 0, 0, ×100, ±1%). Keep one of each in your sample box for quick comparison. Check it on the multimeter before soldering, especially in voltage-divider work, because a swapped 1 kΩ for 10 kΩ silently shifts your reference voltage.

Two common reasons. First, the resistor has a tolerance, so a 1 kΩ ±5% reading 985 Ω is still perfectly fine. Second, your meter leads themselves add resistance — usually 0.2 to 0.5 Ω. There's also temperature drift, oxidation on the leads, and parallel paths if the resistor is still in-circuit. Always lift one leg of the resistor off the board before measuring, and zero out the meter leads first when you are working in the milliohm range.

Yes, most online calculators handle 6-band resistors. The first three are digits, the fourth is the multiplier, the fifth is tolerance, and the sixth band is the temperature coefficient (TCR), measured in ppm per °C. The TCR matters when you build precision references, sensor circuits, or anything that runs hot. For normal house wiring projects we mostly ignore that band, but for instrumentation panels we always specify a low-TCR part.