4 band resistor calculator
| 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% |
A four-band resistor reads as digit, digit, multiplier, tolerance. Yellow-violet-red-gold is 4 then 7, times 100, so 4.7 kΩ at ±5%; meaning anywhere between 4.465 and 4.935 kΩ.
How to read a 4 band resistor
Four bands is the code you will meet most often, because it is the standard marking for the E12 and E24 series that make up ordinary 5% and 2% stock. Two significant digits is exactly enough for those series: every E12 value has two digits, from 10 through 82. If a resistor needs three digits to express, such as 4.99 kΩ, it belongs to a tighter series and will carry five bands instead. So the band count itself tells you something about the precision before you read a single colour.
Questions
4.7 kΩ at ±5%. Yellow is 4, violet is 7, red multiplies by 100.
As a multiplier it means ×0.1, so brown-black-gold is 1 Ω. As the fourth band it means ±5% tolerance.
Usually gold for 5% or silver for 10%. A missing fourth band means ±20%.
Not really. Two digits limits it to the E24 series at best, which is why precision parts use five bands.
Toward the tolerance band, which sits slightly apart from the others.