How to use the Resistor Color Code
- Count the bands and select 4, 5 or 6 band mode.
- Read the bands from the end with more of them grouped together, tolerance band last.
- Select each colour in order and read the resistance and tolerance.
- Confirm with a meter if the bands are faded or ambiguous — brown, red and orange are easily confused.
How the calculation works
The first bands are significant digits, the next is a decimal multiplier, and the final band is tolerance. Four-band resistors give two significant digits, five-band give three for tighter tolerances, and six-band add a temperature coefficient in parts per million per degree. The colour-to-digit mapping is fixed by IEC 60062: black 0 through white 9, with gold and silver reserved for multipliers of 0.1 and 0.01 and for wide tolerances.
Practical values follow the E-series of preferred numbers, so a decoded value that is not close to a standard E12 or E24 value usually means a misread band or a resistor read from the wrong end. The tolerance band, gold at 5% or brown at 1%, is generally separated by a slightly wider gap, which is the clue to orientation.
R = (digits) × 10^multiplier ± tolerance%Source: IEC 60062 marking codes for resistors and capacitors; E-series preferred values per IEC 60063.
Worked example
A four-band resistor marked brown, black, orange, gold.
- Brown = 1, black = 0, giving the digits 10.
- Orange multiplier = ×10³.
- 10 × 1,000 = 10,000 Ω.
- Gold tolerance = ±5%.
10 kΩ ±5%, so any measurement between 9.5 kΩ and 10.5 kΩ is within specification.
Frequently asked questions
Which end do I start reading from?+
Start at the end where the bands are closest together; the tolerance band usually sits slightly apart. If the resistor has a gold or silver band, that is almost always the tolerance and therefore the last band.
Why does my meter read slightly off the coded value?+
Tolerance allows it — ±5% on a 10 kΩ part means anything from 9.5 to 10.5 kΩ is correct. Measure with the resistor out of circuit, since parallel paths lower the reading.
What does the sixth band mean?+
It is the temperature coefficient in ppm/°C, showing how much resistance drifts with temperature. It matters for precision reference and measurement circuits, rarely for general use.
How are surface-mount resistors marked?+
With numbers rather than colours: three or four digits where the last is a multiplier, or an EIA-96 code pairing a two-digit value code with a letter multiplier.
Last reviewed August 31, 2026. We review this page whenever the underlying formula, tax year, published rate or standard changes.