This resistor color band guide lets you read 4-band and 5-band resistors by selecting each color band. The calculated resistance value and tolerance appear instantly. Also includes the complete color code reference table and tolerance specifications.
Resistor Calculator
Color Code Reference
| Color | Digit | Multiplier | Tolerance |
|---|
Mnemonic: Bad Boys Race Our Young Girls But Violet Generally Wins
How to Read Resistor Color Bands
Resistor color bands encode the resistance value and tolerance. Most through-hole resistors use either 4 or 5 bands. Use the calculator above: select each color in order from the end closest to a band (away from the gold/silver tolerance band) to calculate the value instantly.
4-Band Resistor Reading
A 4-band resistor has: Band 1 (first significant digit), Band 2 (second significant digit), Band 3 (multiplier — multiply the two-digit number by this power of 10), Band 4 (tolerance). Example: Orange-Orange-Red-Gold = 3-3-×100-±5% = 3,300Ω = 3.3kΩ ±5%.
5-Band Resistor Reading
A 5-band resistor adds a third significant digit for higher precision. Bands 1-3 are digits, Band 4 is the multiplier, Band 5 is tolerance. Example: Brown-Black-Black-Orange-Brown = 1-0-0-×1000-±1% = 100,000Ω = 100kΩ ±1%.
Which End to Start Reading From
The tolerance band (gold, silver, or colored) is closest to one end of the resistor. Start reading from the opposite end. If the first and last bands are equidistant from the ends, the tolerance band is usually metallic (gold or silver) while the digit bands are non-metallic colors.
Tolerance Meaning
A 10kΩ ±5% resistor could actually measure anywhere from 9,500Ω to 10,500Ω. For sensitive circuits (op-amps, precision voltage dividers), use ±1% or better resistors. For general use (LED current limiting, pull-up resistors), ±5% is fine.
Frequently Asked Questions
Is this resistor color band guide free?
Yes, completely free with no signup required.
Is my data safe when using this tool?
Yes. This reference runs entirely in your browser. No data is sent to any server.
How do I read a 4-band resistor?
A 4-band resistor has: Band 1 (1st digit), Band 2 (2nd digit), Band 3 (multiplier), Band 4 (tolerance). For example, Red-Red-Brown-Gold is 2-2-×10-±5% = 220Ω ±5%.
How do I read a 5-band resistor?
A 5-band resistor has: Band 1 (1st digit), Band 2 (2nd digit), Band 3 (3rd digit), Band 4 (multiplier), Band 5 (tolerance). Used for precision resistors (1% or better). For example, Brown-Black-Black-Red-Brown is 1-0-0-×100-±1% = 10,000Ω = 10kΩ ±1%.
What is the mnemonic for resistor color codes?
A common mnemonic is 'Bad Boys Race Our Young Girls But Violet Generally Wins' — Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White (values 0–9). Other mnemonics include 'Better Be Right Or Your Great Big Venture Goes Wrong.'
What does the gold band mean on a resistor?
A gold band in the tolerance position (last band) indicates ±5% tolerance. Silver indicates ±10%. On a 5-band resistor, gold in the multiplier position means multiply by 0.1 (for values less than 1Ω). Brown = ±1%, Red = ±2%, Green = ±0.5%, Blue = ±0.25%.