Resistor & SMD Decoder
Decode color bands and SMD markings with interactive resistor visualization.
AEO summary
A resistor decoder converts color bands or SMD markings into resistance, tolerance, and expected resistance range.
Use this page when you need a fast answer for through-hole resistor bands or common SMD resistor codes. It helps you match component markings to real electrical values before repair, assembly, or BOM verification.
- Useful for color-band resistors and common SMD code formats.
- Shows both the decoded nominal value and the tolerance-based range.
- Helps confirm whether a part matches a schematic or replacement value.
Supported: 3-digit (`103`), 4-digit (`1004`), `R` notation (`4R7`), and E96 / EIA-96 (`01C`).
E96 quick guide: first two digits = value index, last letter = multiplier.
Common multipliers: Z = ×0.001, Y = ×0.01, X = ×0.1, A = ×1, B = ×10, C = ×100, D = ×1k.
Decoded Value
How to read the result: resistance is the nominal decoded value, tolerance shows permitted variation, and resistance range gives the approximate lower and upper bounds for the actual part.
When selecting a replacement or checking a component, compare the tolerance and range as well as the nominal resistance marking.
Frequently Asked Questions
How do you read resistor color bands?
Resistor color bands are decoded by reading the significant digits first, then the multiplier band, and then the tolerance band according to the standard color code sequence.
What do SMD resistor codes mean?
SMD resistor codes are compact markings that represent resistance values using numeric or alphanumeric formats such as three-digit, four-digit, or E96 style codes.
Resistor Color Code Standards
The resistor color code system, standardized by the IEC 60062 standard, uses colored bands to indicate the resistance value and tolerance of through-hole resistors. The RMA (Radio Manufacturers Association) color coding assigns specific numerical values to each color, enabling rapid identification of component values.
SMD Resistor Marking
Surface Mount Device (SMD) resistors commonly use compact marking systems. This tool supports standard 3-digit codes, 4-digit codes, R notation such as 4R7 for decimal values, and E96 / EIA-96 style codes such as 01C.
For E96 markings, the first two digits point to a preferred-value index and the trailing letter defines the multiplier. Manufacturer-specific variants may still exist, so the decoded value should be cross-checked with the component datasheet when precision matters.
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