Resistor Color Code Calculator
Decode 4, 5, and 6-band resistor color codes into resistance, tolerance, and temperature coefficient.
Resistance
—
Range (with tolerance)
—
For reference and prototyping. Verify any safety- or design-critical value against the component datasheet or a second method before relying on it. Full disclaimer.
About this tool
Set each band's color to read a resistor's value, or use the diagram as a reference for which color means which digit. Supports 4-band (standard), 5-band (precision), and 6-band (precision plus temperature coefficient) resistors, with a live drawing that updates as you choose.
How the code works. The colored bands encode a number in the same left-to-right order every time: significant digits first, then a multiplier (a power of ten), then tolerance, and on 6-band parts a temperature coefficient. A 4-band resistor has two digit bands; 5- and 6-band resistors have three, for one more figure of precision.
The color-to-digit table.
| Color | 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 | — | ±0.05% |
| White | 9 | — | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
Worked example. Brown, black, red, gold on a 4-band resistor: digits 1 and 0 make 10, ×100 (red) gives 1,000 Ω = 1 kΩ, gold tolerance ±5%, so the real value is somewhere between 950 and 1,050 Ω.
Which end to read from. The tolerance band usually has a slightly wider gap before it and sits at one end; start from the other end. Gold and silver are never digit bands, so if one is at an end, that end is the tolerance side. When in doubt, measure with a multimeter — a reversed reading often gives a nonsensically large or small value.
Preferred values. Resistors come in standard series (E12, E24, E96) rather than arbitrary numbers, so a decoded value like 4,700 Ω is common but 4,730 Ω on a 4-band part is not — if you get an odd number, re-check the bands.
To use that value in a circuit, the Ohm's law calculator and resistor power calculator take it from here; for resistors in series or parallel, use the series/parallel calculator. Inductors use a similar scheme — see the inductor color code.
Frequently asked questions
- What's the difference between 4-band and 5-band resistors?
- A 4-band resistor has two significant-digit bands, a multiplier, and a tolerance. A 5-band adds a third digit band for finer precision (1% parts are usually 5-band), and a 6-band adds a temperature-coefficient band as well.
- Which end do I start reading from?
- From the end opposite the tolerance band. The tolerance band (often gold or silver) usually has a wider gap in front of it and sits nearest one end.
- What does a gold or silver band mean?
- Gold and silver are never significant digits. They appear only as a ×0.1 / ×0.01 multiplier or as a ±5% / ±10% tolerance, so they mark the multiplier or tolerance position.
- My decoded value looks unusual — did I misread it?
- Possibly. Real resistors follow standard value series, so an odd number often means the bands were read in the wrong direction or a color was misjudged under poor light. A multimeter check settles it.
- What is the temperature coefficient band for?
- It states how much the resistance drifts with temperature, in parts per million per degree Celsius. It only matters in precision analog circuits.
- Why are some band colors hard to tell apart?
- Brown, red, and orange, or the metallic bands, can look similar under warm or dim light. View the resistor under bright, neutral light, or measure it.