Resistor Color Code Calculator
Decode resistor color bands to find resistance value, tolerance range, and minimum/maximum resistance. Includes color code reference table.
About this calculator
Resistor color bands follow an internationally standardized code (IEC 60062, "Marking codes for resistors and capacitors") that lets a resistance value be printed directly on the component's body instead of requiring legible text on a tiny cylinder. For a standard 4-band resistor, the first two bands encode the significant digits (0-9, black through white), the third band is a multiplier that determines how many zeros to add or, for gold and silver, a fractional multiplier below one, and the fourth band states the manufacturing tolerance -- brown for +/-1%, red for +/-2%, gold for +/-5%, and silver for +/-10%. Because gold and silver appear only as multiplier or tolerance colors and never as digit colors in the standard, this calculator keeps the digit bands and the multiplier/tolerance bands as separate selections rather than one shared color list.
Of the four bands, the multiplier band has by far the largest influence on the resulting resistance: its ten possible values span from x0.01 up to x10,000,000, a spread that dwarfs what either digit band alone can contribute, since the digit bands only combine into a two-digit number from 0 to 99. The tolerance band never affects the calculated resistance value itself -- it only widens or narrows the reported minimum and maximum bounds around that fixed center value.
Inputs
Results
Resistance
4.7 kΩ
Figures current as of 2016. Source: International Electrotechnical Commission, IEC 60062:2016, Edition 6.0, "Marking codes for resistors and capacitors"
How to Use This Calculator
- Select the color for each band: band 1 (first digit), band 2 (second digit), multiplier, and tolerance.
- The calculator combines the two significant digits with the multiplier band to compute the resistance.
- Review the decoded resistance value in ohms, tolerance (%), and min/max resistance range.
- Check the color code reference table to confirm each band's digit and multiplier meaning.
- The mnemonic 'Bad Boys Race Our Young Girls But Violet Generally Wins' helps remember the color order.
What each input means
- Band 1 (1st Digit)
- Color of the first resistor band.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersBand 1 (1st Digit) = 4, Band 2 (2nd Digit) = 7, Band 3 (Multiplier) = 2, Tolerance Band = 2 = 4 input(s) provided
- Calculate ResistanceResistance = resistanceStr4.7 kΩ = 4.7 kΩ
- Calculate ToleranceTolerance5 = 5
- Calculate Min ResistanceMin Resistance4465 = 4465
Figures and sources
- IEC 60062:2016 — Marking codes for resistors and capacitors (resistor color code) (2016) — International Electrotechnical Commission, IEC 60062:2016, Edition 6.0, "Marking codes for resistors and capacitors"
Engine last updated . Checked against 3 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why can't gold or silver be used as a digit band color?
IEC 60062, the international standard ("Marking codes for resistors and capacitors") that defines this whole color scheme, reserves gold and silver specifically for the multiplier band (as fractional multipliers below 1) and the tolerance band (5% and 10% respectively) -- they were never assigned digit meanings. That's why this calculator's digit-band selectors only offer black through white, while gold and silver only appear as options on the multiplier and tolerance bands.
How much does the multiplier band change the resistance compared to the digit bands?
Far more. The two digit bands together only produce a base number from 0 to 99, but the multiplier band spans from x0.01 to x10,000,000 across its ten color options -- a range of nine orders of magnitude. Picking the wrong multiplier color, even with the correct digits, produces a resistance that is off by a power of ten or more.
Does changing the tolerance band affect the calculated resistance value?
No -- the tolerance band only widens or narrows the reported minimum and maximum resistance range around a resistance value set entirely by the digit and multiplier bands. A gold (+/-5%) tolerance band produces a tighter min/max spread than a silver (+/-10%) band, but the center resistance value itself stays identical either way.
What's a quick way to remember the resistor color-to-digit order?
A common mnemonic runs Black-Brown-Red-Orange-Yellow-Green-Blue-Violet-Gray-White for digits 0 through 9, following the same order as a rainbow with black and white added at the ends. Many electronics students memorize it as a sentence where each word's first letter matches a color, in that same 0-9 sequence.
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