Resistor color code calculator: 4, 5 and 6 bands
4-, 5- and 6-band resistor color code calculator with resistance in ohms, tolerance range and temperature coefficient.
Select the number of bands and each color. Significant digits, multiplier, tolerance and temperature coefficient are applied automatically.
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How does this tool work?
Axial resistor color codes encode nominal resistance with significant-digit bands, a multiplier and a tolerance. Six-band resistors generally add a temperature coefficient in ppm/K.
With four bands, the first two are significant digits, the third is the multiplier and the fourth is tolerance.
With five bands, three significant digits are used before the multiplier, providing a finer nominal value.
With six bands, the sixth band represents temperature coefficient when the selected color has a defined ppm/K value.
How to use this tool
Find the reading direction
Place the tolerance band on the right when it can be identified. It is often separated by a larger gap and is commonly gold, silver or a low-tolerance color. Read the remaining bands from left to right.
Choose 4, 5 or 6 bands
Four-band codes use two significant digits. Five- and six-band codes use three significant digits before the multiplier, while the sixth band adds a temperature coefficient.
Apply digits, multiplier and tolerance
The calculator turns the significant bands into a number, applies the multiplier and then uses tolerance to calculate the minimum and maximum expected resistance around nominal.
Interpret the sixth band
For a six-band resistor, the final color can encode temperature coefficient in ppm/K, describing how sensitive resistance is expected to be to temperature change.
Good to know
Four and five bands use different numbers of significant digits
A four-band resistor has two significant digits before the multiplier, while a five-band resistor has three. Selecting the correct band count is therefore essential before interpreting the same colors.
Tolerance defines a range, not a correction
A 1 kΩ ±5% resistor is not automatically adjusted by five percent. Its expected value simply lies between 950 Ω and 1050 Ω under the specified conditions.
Temperature coefficient is different from tolerance
Tolerance describes the allowed initial deviation around nominal resistance. The ppm/K coefficient instead describes the expected relative change in resistance as temperature changes.
Reading the bands
The resistor color code maps colors to significant digits, a multiplier and tolerance. A six-band code can also include temperature coefficient in parts per million per kelvin.
Nominal value
R = significant digits × multiplier
Tolerance then defines the interval around R.
The calculator decodes the selected bands according to their positions. On a physical component, also verify orientation, marking condition and electrical measurement.
Use cases
Identifying a resistor on a board
Read an axial component whose resistance is not printed as text. Reproduce the band order visually and get the nominal value immediately in Ω, kΩ or MΩ.
Checking a part before assembly
Compare the decoded value with a schematic or bill of materials before soldering. The minimum and maximum values also remind you that a real component can vary within its tolerance.
Learning resistor color codes
Learn the role of each band rather than memorizing isolated examples. Switching between 4, 5 and 6 bands makes the difference between significant digits, multiplier, tolerance and temperature coefficient explicit.
Comparing with a multimeter reading
Check whether a measured resistance falls inside the theoretical tolerance interval. An out-of-range value can reflect the component, temperature, in-circuit measurement paths or test conditions.
Examples
Brown, black, red, gold
10 × 100 Ω = 1000 Ω.
Input
4 bandsResult
1 kΩ ±5%Brown, black, black, red, brown
100 × 100 Ω = 10,000 Ω.
Input
5 bandsResult
10 kΩ ±1%Tips and best practices
- Read the resistor in the correct direction; the tolerance band is often spaced farther away.
- Gold and silver are multiplier or tolerance colors, not significant digits.
- For a physical component, compare with a multimeter while allowing for tolerance.
- If the reading direction is unclear, identify the tolerance band and spacing before treating the colors as digits.
- Measuring a resistor while it is still connected to a circuit can alter the multimeter reading because other current paths may be present.
Sources and references
- DigiKey, Resistor Color Code Calculator — 4 band, 5 band, 6 band (opens in a new tab)Page in English
- IEC 60062:2016+AMD1:2019 — Marking codes for resistors and capacitors (opens in a new tab), International Electrotechnical Commission, 2019Page in English
- OpenStax, 9.4 Ohm's Law (opens in a new tab), University Physics Volume 2Page in English
Frequently asked questions
What is the difference between 4 and 5 bands?
Five-band codes use three significant digits rather than two.
What does the sixth band mean?
It commonly gives the temperature coefficient in ppm/K.
What does ±5% mean?
The actual resistance may lie within ±5% of nominal value.
Can gold or silver be a first digit?
No. They are used for multiplier or tolerance roles.
How do I know which end to start from?
The tolerance band is often spaced farther from the others and placed on the right. Gold and silver are useful clues because they are not used as first significant digits.
What does ppm/K mean on a six-band resistor?
It is a relative change per million per kelvin. For example, 50 ppm/K corresponds to a nominal change of 0.005% per kelvin.
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