Resistor Color Code Calculator
Click the colour bands on the resistor to read its value, or type a value to see which bands to use. Supports 4, 5, and 6-band resistors with a live visual that updates as you work.
Band count
Mode
Band colors
E-series match
3-digit (e.g. 472 = 4.7 kΩ), 4-digit (e.g. 4702 = 47 kΩ), or EIA-96 (e.g. 01A = 100 Ω)
Bill of Materials
Resistor Color Code Reference
Full color code chart for all 12 colors. The digit column applies to bands 1, 2, and 3. Multiplier is applied after the digits. Tolerance and temperature coefficient only appear in later bands.
| Color | Digit | Multiplier | Tolerance | Temp. coeff. (ppm/°C) |
|---|
How to read resistor color bands
4-band resistors are the most common type. The first two bands are the first two significant digits, the third band is the multiplier (a power of ten), and the fourth band (usually Gold or Silver) is the tolerance. Gold means 5%, Silver means 10%.
5-band resistors are used for precision resistors (1% tolerance and tighter). Bands 1-3 are significant digits, band 4 is the multiplier, and band 5 is the tolerance. Brown = 1%, Red = 2%, Green = 0.5%.
6-band resistors add a sixth band for the temperature coefficient (how much the resistance changes per degree Celsius). Brown = 100 ppm/C, Red = 50 ppm/C, Orange = 15 ppm/C.
E-series standard values (E12, E24, E48, E96) are the preferred resistance values used in manufacturing. E24 has 24 values per decade and is the most common. If your target resistance isn't an E24 value, this calculator shows the nearest standard value and the percentage difference.
Reading tip: Hold the resistor with the tolerance band (Gold/Silver) to the right. The remaining bands, read left to right, give you the value. If all four bands look like they could be digit colors (none is Gold or Silver), try rotating the resistor 180 degrees.
Learn more: reading resistor color bands
4, 5 and 6 bands
A 4-band resistor has two digit bands, a multiplier and a tolerance. A 5-band one has three digits, a multiplier and a tolerance, and a 6-band one adds a temperature coefficient band. Wikipedia's electronic color code article calls this the four-five rule: four or fewer bands mean two digit bands, and five or more mean three, though it notes many exceptions. It says a sixth solid band can give a temperature coefficient in ppm/K.
Yellow, violet, red and gold is 47 x 100 = 4,700 ohms with a 5% tolerance, which the tool writes as 4.7 kohm. In the tool a 5% (gold) 220 ohm part can measure from 209 to 231 ohms and still be in spec.
Which end to start from
The same article gives two clues. A gold or silver band marks the tail end, so you read from the other end. Failing that, the end where the bands sit closer together, the tighter end, is the head.
E-series values
Wikipedia's E series article says the IEC began work on preferred values in 1948 and published IEC 63 in 1952, which became IEC 60063. The values follow a geometric progression, so each step is the same percentage. E12 is for 10% parts with 12 values per decade, E24 for 5% with 24, E48 for 2% with 48 and E96 for 1% with 96.
The tool finds the nearest E12, E24 and E96 value for a resistance. It checks against the next decade's 1.0 as well, so 970 ohms goes to 1000 and not 910 in E24.
SMD codes
The same color code article notes that SMD parts use printed alphanumeric codes and not bands. The tool decodes three formats. In a 3-digit code, 472 is 47 x 10^2 = 4,700 ohms. In a 4-digit code the first three digits are the value, so 4702 is 470 x 10^2 = 47,000 ohms. An EIA-96 code is two digits that look up a value plus a letter multiplier, so 01A is 100 ohms and 68C is 49,900 ohms.
FAQ
How do I know which end to read from?
Look for a gold or silver band, which marks the tail end. Otherwise start from the end where the bands are bunched closer together.
What does the tolerance band mean?
It is the accuracy range around the marked value. A 220 ohm resistor with a gold band can be anywhere from 209 to 231 ohms.
How do I decode a 3-digit SMD code like 472?
The first two digits are the value and the last is the power of ten, so 472 is 47 x 100 = 4,700 ohms, or 4.7 kohm.