Resistor Color Code Calculator
Choose the number of bands and pick the colors, or switch to the other mode, type a resistance and get the bands. You get the resistance, the tolerance and the range.
Your numbers
How we calculate it
On a 4 band resistor the first two bands are digits, the third is the multiplier and the fourth is the tolerance. A 5 band resistor has three digit bands, and a 6 band resistor adds a temperature coefficient band. The digit colors are black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8 and white 9. The multiplier is 10 to the power of the color's digit, with gold meaning × 0.1 and silver × 0.01.
For example, yellow, violet, red, gold is 47 × 100 = 4,700 Ω = 4.7 kΩ with a tolerance of ±5%, so the real value lies between 4.465 kΩ and 4.935 kΩ. In the other direction, the calculator finds the digits and the multiplier for a resistance, and tells you the nearest values if it cannot be written with that many digits.
Assumptions and limits
- Read the bands from the end that has the bands closer together. The tolerance band is usually gold or silver on 4 band resistors and is set a little apart from the others.
- With 4 bands only two digits can be shown, so 4,750 Ω needs 5 bands. A 4 band resistor covers 0.1 Ω to 99 GΩ.
- The color table follows the IEC 60062 code. Temperature coefficient colors can vary a little between makers, so check the data sheet when the value matters.
Frequently asked questions
How do I read a resistor color code?
Write down the digits from the first bands, multiply by the multiplier band, and note the tolerance. Yellow, violet, red is 4, 7, then × 100, so 4,700 Ω.
What does the gold band mean?
On the end of a 4 band resistor gold is the tolerance, ±5%. In the multiplier position gold means × 0.1, which is used for values below 10 Ω.
What is the difference between 4, 5 and 6 band resistors?
More bands mean more precision. A 5 band resistor has three digits and a tighter tolerance, often ±1%. A 6 band resistor also gives the temperature coefficient in parts per million per kelvin.
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Worked example (a fixed example using the starting numbers, it does not change as you type)
Inputs: Mode = Read the colors (colors to value); Number of bands = 4 bands; Band 1 (first digit) = Yellow; Band 2 (second digit) = Violet; Band 3 (third digit, 5 and 6 bands only) = Black; Multiplier band = Red (× 100); Tolerance band = Gold (±5%); Temperature coefficient band (6 bands only) = Brown (100 ppm/K).
- Resistance 4.7 kΩ
- Tolerance ±5%
- Range 4.465 kΩ to 4.935 kΩ
- Color bands yellow, violet, red, gold
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