Resistor Colour Code Calculator
A resistor’s value and tolerance range from its colour bands, or the bands for a value, snapped to the nearest E12, E24 or E96 preferred value.
Result
Resistance: 4.7 kΩ
Start reading from the end the bands are bunched towards; the tolerance band is usually set apart.
- Tolerance
- 5%
- Lowest within tolerance
- 4.465 kΩ
- Highest within tolerance
- 4.935 kΩ
- Bands, in order
- Yellow, Violet, Red, Gold
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Results come from the published equations applied to the values you enter. They are not electrical design, conductor sizing, laboratory safety or medical guidance. Weather indices describe a standard person in standard conditions and are not a forecast. Where codes apply, local rules vary and must be checked. Read the full disclaimer
How to use the Resistor Colour Code Calculator
- Choose whether to read a value from the bands, or to find the bands for a value.
- To read, choose 4 or 5 bands and pick each band's colour; each option names its colour and what it means.
- To find the bands, enter the resistance and a preferred value series, and read the nearest standard value and its bands.
Reading the bands
On a 4-band resistor, the first two bands are digits, the third is a power of ten to multiply by, and the fourth is the tolerance. A 5-band resistor has three digits before the multiplier, for 1% and tighter parts. A 3-band resistor is a 4-band one with no tolerance band, meaning ±20%.
| Colour | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | |
| Brown | 1 | ×10 | 1% |
| Red | 2 | ×100 | 2% |
| Orange | 3 | ×1,000 | |
| Yellow | 4 | ×10,000 | |
| Green | 5 | ×100,000 | 0.5% |
| Blue | 6 | ×1,000,000 | 0.25% |
| Violet | 7 | ×10,000,000 | 0.1% |
| Grey | 8 | ×100,000,000 | 0.05% |
| White | 9 | ×1,000,000,000 | |
| Gold | ×0.1 | 5% | |
| Silver | ×0.01 | 10% |
Yellow, violet, red, gold reads 4, 7, then two zeros: 4,700 Ω, written 4.7 kΩ, at 5%.
Finding the bands
A value from a calculation rarely matches a resistor you can buy. The page snaps it to the nearest value in the series you choose, by ratio rather than difference, and gives that value’s bands: 4 bands for E12 and E24, 5 for E96.
The code is defined by the international standard IEC 60062 and the preferred values by IEC 60063. A sixth band, when present, gives the temperature coefficient and is not decoded here.
With your numbers
- Yellow, Violet, Red, Gold: 4,700 Ω ± 5%
Quick reference
Start reading from the end the bands are bunched towards; the tolerance band is usually set apart.
| Example | Resistance |
|---|---|
| Yellow, violet, red, gold | 4.7 kΩ |
| Brown, black, orange, gold | 10 kΩ |
| Red, red, brown, gold | 220 Ω |
| Brown, black, black, red, brown | 10 kΩ |
| Green, blue, gold, gold | 5.6 Ω |
| Brown, black, silver, gold | 0.1 Ω |
| Bands for 4.7 kΩ, E24 | 4.7 kΩ |
Common questions about the Resistor Colour Code Calculator
- How do I know which end to start from?
- The tolerance band, often gold or silver, is usually set a little apart from the others, or wider. Start from the other end. A resistor never starts with a gold or silver band, and very rarely with black.
- Why can gold and silver be the third band?
- In the multiplier position they mean ×0.1 and ×0.01, for values under 10 Ω. Green, blue, gold, gold is 56 × 0.1 = 5.6 Ω at 5%. Treating gold only as a tolerance colour is the most common mistake in reading them.
- What does the tolerance range mean?
- How far the actual resistance may be from the marked value. A 4.7 kΩ resistor at 5% can measure anywhere from 4,465 to 4,935 Ω and still be within specification. The range is usually more useful than the percentage.
- What are E12, E24 and E96?
- Series of preferred values, spaced so each tolerance band just overlaps the next. E12 has twelve values per decade for 10% parts, E24 twenty-four for 5%, E96 ninety-six for 1%. Resistors are made in these values, so a value from a calculation is usually rounded to the nearest one.