Resistor Color Code Decoder
Pick the colour bands and read the resistance and tolerance instantly — 4-band and 5-band supported.
What it does: Translate the colour bands on a resistor into a resistance and tolerance.
When to use it: When you have a resistor of unknown value or can't read the markings.
Left to right: the digit bands, then the multiplier band? , then the tolerance band? .
MEANS This resistor is nominally —, with an actual value between —.
No history yet. Each calculation is automatically saved to this device.
Read the guide: How to read resistor color codes (4/5/6 band)
How to use the colour code decoder
Pick the colours and the result appears.
- 01
Pick the number of bands
Common resistors have
4 bandsor5 bands. 5 bands is more precise (one more significant digit). - 02
Pick each band colour left to right
The first few bands are significant digits, the second-to-last is the multiplier, and the last (usually gold/silver) is the tolerance.
- 03
Read the resistance
The tool gives the resistance and tolerance in real time and draws the corresponding band diagram.
Colour band reference (IEC 60062)
The digit, multiplier, and tolerance bands use the same set of colours but with different meanings.
| Colour | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1k | — |
| Yellow | 4 | ×10k | — |
| Green | 5 | ×100k | ±0.5% |
| Blue | 6 | ×1M | ±0.25% |
| Violet | 7 | ×10M | ±0.1% |
| Grey | 8 | ×100M | ±0.05% |
| White | 9 | ×1G | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
Data from IEC 60062 (marking codes for resistors and capacitors).
Common questions, answered in 3 minutes
How do I tell which end to start reading from?
The tolerance band (often gold or silver) is usually closer to a lead and spaced slightly farther from the others; put it on the right and read from the other end toward the right.
What is the difference between 4 and 5 bands?
4 bands = 2 significant digits; 5 bands = 3 significant digits, which is more precise. The reading method is the same, just one extra digit band.
Are gold and silver always tolerance?
In the last band they are tolerance (gold ±5%, silver ±10%); in the multiplier position they mean ×0.1 / ×0.01, used for resistors below 10Ω.
What if there is no tolerance band (only 3 bands)?
The default tolerance is ±20%. This tool is designed for standard 4/5-band parts; for a 3-band part, treat the fourth band as "no colour, ±20%".
Standards and sources referenced by this tool
| Item | Value / Formula | Source |
|---|---|---|
| Digit / multiplier / tolerance colour table | black=0 … white=9; gold=×0.1; gold=±5% | IEC 60062 (resistor & capacitor marking) |
Band meanings from the IEC 60062 standard table, no external API.