Resistor Colour Code Calculator
Click the colour bands to decode any resistor value instantly. Supports 4-band and 5-band resistors with full tolerance display.
How to Use This Calculator
Select 4-Band or 5-Band mode, then click each band button to cycle through colours. The resistance value and tolerance update instantly. Use 4-band for standard resistors and 5-band for precision resistors (1% tolerance and tighter).
Formula
4-Band: The first two bands are digits, the third is the multiplier, the fourth is tolerance.
5-Band: Three significant digits, then multiplier, then tolerance.
Where D1, D2, D3 are the digit values of each colour band and Multiplier is the power-of-ten factor.
Colour Code Reference Table
| Colour | Digit | Multiplier | Tolerance |
|---|
Frequently Asked Questions
How do I read a 4-band resistor?
Hold the resistor so the tolerance band (gold or silver) is on the right. Read the first two bands as digits, the third as a multiplier, and the fourth as tolerance. For example: Brown–Black–Red–Gold = 1, 0, ×100, ±5% = 1000 Ω (1 kΩ).
What is the difference between 4-band and 5-band resistors?
5-band resistors have three significant digit bands instead of two, giving greater precision. They are common in 1% tolerance (E96 series) resistors used in precision circuits.
What do gold and silver bands mean?
As a tolerance band: Gold = ±5%, Silver = ±10%. As a multiplier band: Gold = ×0.1, Silver = ×0.01 — used for values below 10 Ω.
Which end of the resistor do I start reading from?
Start from the end closest to the first coloured band. The tolerance band (gold, silver, or occasionally brown for 1%) is always closest to the opposite end and is usually separated by a slightly larger gap.
Why does my resistor not match a standard E-series value?
Resistors are manufactured in standard value series (E12, E24, E96). If your calculated value seems unusual, double-check the band colours — brown and red, or orange and yellow, are easy to confuse under certain lighting.