SMD Resistor Code Calculator

SMD Resistor Code Calculator supports engineering calculations with transparent assumptions, practical result interpretation, and links to next-step technical resources.

Decode 3-digit, 4-digit, EIA-96, and low-ohm R-mark SMD resistor codes.

Legend & Decode Visualization

Supported Formats

3-digit: `472` → 4.7 kΩ

4-digit: `1001` → 1 kΩ

EIA-96: `01C` → 10 kΩ

Low-ohm: `4R7` → 4.7 Ω

Input is case-insensitive and spaces are ignored.

SMD Chip Preview

Decode Breakdown

Enter a marking to show decode details.

Equivalent Marking Suggestions

Decode a valid resistor value to get equivalent code suggestions.

Inputs & Outputs

SMD Marking

Tip: For EIA-96, use two digits + letter (example: `49B`).

Output

Decoded Resistance

Decode Scheme

Tolerance Hint

Engineering Note

SMD Marking Schemes

Different package families and tolerance classes use different code systems.

Scheme	Pattern	Interpretation	Example
3-digit code	XYM	First 2 digits are significant, third digit is multiplier power.	472 = 47 × 10² = 4.7 kΩ
4-digit code	XYZM	First 3 digits are significant, fourth digit is multiplier power.	1001 = 100 × 10¹ = 1 kΩ
EIA-96 code	NNL	NN maps to E96 base value; letter defines multiplier.	01C = 100 × 100 = 10 kΩ
Low-ohm R mark	nRn / Rnn	R replaces decimal point for fractional-ohm values.	4R7 = 4.7 Ω, R22 = 0.22 Ω

EIA-96 Multiplier Quick Reference

Letter	Multiplier	Typical Range
Z	×0.001	Sub-ohm precision values
Y / R	×0.01	Low-ohm values
X / S	×0.1	Fractional-ohm to tens-ohm
A	×1	Base E96 values
B	×10	kΩ-entry range
C	×100	kΩ to MΩ transition
D / E / F	×1k / ×10k / ×100k	High-value precision resistors

Production Handling Matrix

Scenario	Recommendation	Risk if Ignored
Rework and repair in mixed BOM boards	Always decode marking and cross-check with circuit function before replacement.	Wrong decade can shift bias, thresholds, or current limit drastically.
Incoming QC for reels and cut tapes	Sample decode against purchase MPN and measured spot-check values.	Mis-labeled reels create latent production escapes.
Failure analysis of burnt or discolored parts	Use marking decode + surrounding topology + measured pads for reconstruction.	Part code alone may be ambiguous under heat damage.