How it works
Decode the first two bands as decimal digits, apply the third-band multiplier and use the fourth band as percentage tolerance.
Input definitions
- First digit
- Choose Brown / Red / Orange / Yellow / Green / Blue / Violet / Gray / White.
- Second digit
- Choose Black / Brown / Red / Orange / Yellow / Green / Blue / Violet / Gray / White.
- Multiplier band
- Choose Black / Brown / Red / Orange / Yellow / Green / Blue / Violet / Gray / White / Gold / Silver.
- Tolerance band
- Choose Brown / Red / Green / Blue / Violet / Gray / Gold / Silver / None.
A worked example
- First digit
- Brown
- Second digit
- Black
- Multiplier band
- Red
- Tolerance band
- Gold
Assumptions & limits
Four-band axial resistor convention only; color appearance and orientation can be ambiguous. No power-rating or component-health assessment.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Can this decode a five-band or six-band resistor?
No. It supports the four-band scheme with two significant digits, a multiplier and tolerance. Five- and six-band markings need a different interpretation.
How does Four-band resistor color decoder work?
Decode the first two bands as decimal digits, apply the third-band multiplier and use the fourth band as percentage tolerance.
What are the limits of Four-band resistor color decoder?
Four-band axial resistor convention only; color appearance and orientation can be ambiguous. No power-rating or component-health assessment.