It is sometimes not obvious whether a color coded component is a
resistor, capacitor, or inductor, and this may be deduced by knowledge
of its circuit function, physical shape or by measurement. Resistor
values are always coded in ohms
(symbol ?), capacitors
(pF), and inductors
To distinguish left from right there is a gap between the C and D bands.
- band A is first significant figure of component value (left side)
- band B is the second significant figure
- band C is the decimal multiplier
- band D if present, indicates tolerance of value in percent (no color means 20%)
For example, a resistor with bands of yellow, violet, red, and gold
will have first digit 4 (yellow in table below), second digit 7
(violet), followed by 2 (red) zeros: 4,700 ohms. Gold signifies that the
tolerance is ±5%, so the real resistance could lie anywhere between
4,465 and 4,935 ohms.
Resistors manufactured for military use may also include a fifth band which indicates component failure rate (reliability
); refer to MIL-HDBK
-199 for further details.
Tight tolerance resistors may have three bands for significant figures rather than two, and/or an additional band indicating temperature coefficient
, in units of ppm
All coded components will have at least two value bands and a multiplier; other bands are optional (italicised below).
The standard color code per EN 60062
:2005 is as follows:
Temp. Coefficient (ppm/K)
- Any temperature coefficent not assigned its own letter shall be marked "Z", and the coefficient found in other documentation.
- For more information, see EN 60062.
- Yellow and Gray are used in high-voltage resistors to avoid metal particles in the lacquer.
A resistor which (read left to right) displays the colors yellow, violet, yellow, brown
. The first two bands represent the digits 4
. The third band, another yellow
, gives the multiplier 104. The value is then 47 x 104 ?
, or 470 k?
. The brown band shows a tolerance of ±1%.
Resistors use Preferred numbers
for their specific values, which are determined by their tolerance
. These values repeat for every decade of magnitude: 6.8, 68, 680, and so forth.
Zero ohm resistors
are made as lengths of wire wrapped in a resistor-shaped body which can
be substituted for another resistor value in automatic insertion
equipment. They are marked with a single black band.
The 'body-end-dot' or 'body-tip-spot' system was used for radial-lead
composition resistors sometimes found in very old equipment; the first
band was given by the body color, the second band by the color of the
end of the resistor, and the multiplier by a dot or band around the
middle of the resistor. The other end of the resistor was colored gold
or silver to give the tolerance, otherwise it was 20%
Extra bands on ceramic capacitors will identify the voltage rating class and temperature coefficient characteristics.
A broad black band was applied to some tubular paper capacitors to
indicate the end that had the outer electrode; this allowed this end to
be connected to chassis ground to provide some shielding against hum and
Polyester film and "gum drop" tantalum electrolytic capacitors are
also color coded to give the value, working voltage and tolerance.