How to use this calculator
- Enter or choose number of bands.
- Enter or choose band 1 (first digit).
- Enter or choose band 2 (second digit).
- Enter or choose band 3 (third digit, 5 and 6 bands only).
- Enter or choose multiplier band.
- The resistance updates as you type. Use Copy result or Share to keep it.
Method
Resistance = (digits) × multiplier; Range = Resistance × (1 ± tolerance ÷ 100). Digits: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Multiplier: 10^digit, gold × 0.1, silver × 0.01.
- Tolerance
- brown ±1%, red ±2%, green ±0.5%, blue ±0.25%, violet ±0.1%, grey ±0.05%, gold ±5%, silver ±10%, no band ±20%
Worked example
- Brown = 1 and green = 5 give the digits 15.
- Red multiplier = × 100, so 15 × 100 = 1,500 Ω = 1.5 kΩ.
- Gold = ±5%: 1,500 × 0.05 = 75 Ω, so 1,425 to 1,575 Ω.
Brown-green-red-gold is a 1.5 kΩ resistor with ±5% tolerance, anywhere from 1,425 Ω to 1,575 Ω.
What the result means
Check a decoded value against the standard E-series (E12, E24…) values: if the result is not a standard value, you have probably read the bands from the wrong end. A multimeter settles any doubt.
Assumptions and limits
- IEC 60062 colour code as commonly used for through-hole resistors.
- Grey and yellow tolerance markings vary between manufacturers and editions of IEC 60062 (grey is also used for ±0.01%); check the datasheet for precision parts.
- Surface-mount resistors use printed number codes, not colours.
Questions
Which end do I start from?
Start from the end with the band closest to the edge. The tolerance band, often gold or silver, is usually separated by a wider gap and goes last.
What does a single black band mean?
A zero-ohm link: a jumper in a resistor body.